In the
 United States Court of Appeals
              For the Seventh Circuit
                        ____________

No. 06-4395
E.C. STYBERG ENGINEERING COMPANY,
                                          Plaintiff-Appellant,
                              v.


EATON CORPORATION,
                                          Defendant-Appellee.
                        ____________
          Appeal from the United States District Court
             for the Eastern District of Wisconsin.
          No. 03-C-0571—David R. Herndon, Judge.
                        ____________
       ARGUED JUNE 1, 2007—DECIDED JULY 9, 2007
                    ____________


 Before FLAUM, MANION, and ROVNER, Circuit Judges.
   FLAUM, Circuit Judge. E.C. Styberg Engineering Co.
(“Styberg”) sued Eaton Corp. (“Eaton”), claiming that
it breached a contract to buy 13,000 transmission compo-
nents from Styberg. After a bench trial, the district court
found that no contract existed and entered judgment
for Eaton. Styberg appeals, and, for the following reasons,
we affirm.


                     I. BACKGROUND
 Styberg manufactures custom components for other
manufacturers, and Eaton manufactures, among other
2                                                    No. 06-4395

things, motor vehicle parts and accessories, including
transmissions. From 1998 to 2000, Styberg manufactured
Part No. A-6871, an Inertia Brake Assembly (“I-brake”),
for Eaton’s six-speed transmissions. In August 1998,
Styberg began selling prototype I-brake units to Eaton,
and, in November, Eaton began purchasing limited
quantities of I-brakes so it could test the product in the
marketplace. Subsequently, Eaton decided to pursue full
production of I-brakes, and, in 1999, the parties began
negotiating an agreement under which Styberg would
produce large quantities of I-brakes for Eaton.
  As negotiations proceeded, John Baker, Styberg’s
Engineering and Quality Assurance Manager, kept in
contact with two Eaton employees: Al Davis, an engineer,
and Lisa Fletcher, Eaton’s buyer.1 On May 27, 1999, Davis
sent Baker an e-mail expressing Eaton’s willingness to
make a minimum purchase commitment to Styberg. Davis
stated,
      I know that Styberg wants a commitment for a mini-
      mum number of units that Eaton will buy (to protect
      Styberg’s capital expenditures). I believe Eaton is
      willing to give Styberg that commitment as well. . . .
      At the very least, I believe Eaton will guarantee the
      number of units it takes to pay off your capital invest-
      ments, however many that is. (like the 13,000 we
      were discussing before) . . . .
Getting a minimum unit commitment from Eaton was
important to Styberg because, as Davis’ e-mail suggests,
Styberg had to expend significant capital to mass-produce
the custom-designed parts.
  On July 8, 1999, Baker sent Fletcher a proposal for a
60,000 unit order. According to the proposal, the first


1
    Fletcher died before trial and was only partially deposed.
No. 06-4395                                               3

13,000 units sold would have an average price of $544.88.
The initial price of the units would be $595, but the price
would progressively decrease as Styberg tweaked and
perfected its manufacturing process. The proposal con-
tained additional conditions, including a re-evaluation of
the price and delivery schedule after the first 6,000 units
were produced and an additional $31 per unit charge until
a certain snap-in coil became available for manufacturing.
Furthermore, the proposal requested $343,000 in “tooling
money”– money that would assist Styberg in acquiring
materials for its customized production. It also stated that
Styberg would begin full production of the I-brakes in six
months.
  In his telephone log from July 16, 1999, Baker wrote,
“Lisa Fletcher Quote was received. We have the 13,000
order!” A few days later, on July 22 and 23, Davis was
visiting Styberg and met with its Vice President of Manu-
facturing, Ron Jones. Jones asked Davis for Eaton’s
commitment to buy at least 60,000 units, or, in the alter-
native, to buy 20,000 units with an additional capital
investment of $1.2 million. Davis did not respond to the
request while he was on site. On July 26, he e-mailed
Fletcher, noting that Styberg representatives had indi-
cated that they needed “a larger total unit commitment
[than 13,000]” before the company would increase its
monthly production capacity.
  In a letter to Baker dated July 29, 1999, Fletcher wrote:
    Enclosed please find a tooling commitment . . . . [W]ith
    this $293,000 investment Styberg will be able to
    produce assembly A-6971 at a rate of up to 1,400 units
    per month, with an approximate lead time of four
    months.
    Eaton will purchase a minimum of 13,000 units at
    an average unit price of $544.88 by July 29th, 2001.
    Additional requirements will be based on the market
4                                               No. 06-4395

    competitiveness and product value as the initial 13,000
    units are consumed. . . .
On August 9, 1999, Baker and Fletcher spoke on the
telephone and Baker told Fletcher, “thank you.” According
to Baker, he said “thank you” to indicate to Fletcher that
Styberg agreed to produce the minimum quantity at the
average price. However, Baker’s notes from the phone
call say, “13,000 units doesn’t cover [Styberg’s capitaliza-
tion for the project] . . . 25 to Ron’s 30,000.” During cross-
examination, Baker acknowledged that the notation
meant that Styberg’s Vice President of Manufacturing
wanted a 25,000 to 30,000 unit commitment.
  On September 1, 1999, employees from both companies
participated in a conference call. Fletcher’s notes from the
call state, “we commit to 13K units—Styberg sez [sic] not
enough to justify their capital investment. Want at
least 30K commitment. . . . Styberg will come back w/
capacity + quotes for 13K flat out.” According to Baker, the
parties to the conference call agreed that, in regard to
the 13,000 unit order, Baker would prepare a schedule
for Fletcher that detailed the number of units Styberg
could produce each month with its present capital.
  On September 9, 1999, Baker sent Fletcher a produc-
tion schedule that included a detailed break-down of
Styberg’s anticipated monthly production capacity for
13,000 units as well as a quote for an initial unit price of
$595 plus $31 per unit until the snap-in coil became
available. The quote stated that the estimated delivery
date would “be based on a starting date four months
after an agreement on casting design, unit price, and
delivery schedules.” Baker testified that on September 27,
1999, Fletcher told him that the schedule was acceptable.
However, Baker’s notes from September 27 include the
notation “LM,” which, according to earlier testimony,
meant that he left a message for Fletcher and did not
speak with her.
No. 06-4395                                                    5

  Eaton did not issue a specific purchase order for the
13,000 I-brakes, but Baker contends that Fletcher told
him to use an existing purchase order. Styberg did not
execute or send Eaton a purchase order acknowledgment
for the 13,000 unit order. In April 2000, Eaton notified
Styberg that it expected delivery of 240 units. Styberg
shipped the units under an existing purchase order, and
Eaton paid for the units. On May 8, 2000, Eaton re-
quested another 240 units for shipment, which were to be
delivered the following month. Three days later, however,
Eaton cancelled the request. After May 11, 2000, Eaton
neither ordered nor paid for any I-brakes. In May 2003,
after settlement discussions broke down, Styberg sued
Eaton in the district court for breach of contract, seeking
approximately $3.4 million in damages, which repre-
sented Styberg’s lost profits and inventory related to the
manufacture of 13,000 I-brakes.2
  After a four-day trial, the district court entered judgment
in favor of Eaton, summarizing the case as follows:



2
  This case is in federal court pursuant to 28 U.S.C. § 1332,
which confers federal jurisdiction where the parties are citizens
of different states and the amount in controversy exceeds
$75,000. Styberg is a Wisconsin corporation with its principal
place of business in Wisconsin; Eaton is an Ohio corporation
with its principal place of business in Ohio; and Styberg seeks
more than $3 million from Eaton. The dispute is governed
by Ohio law because Eaton’s purchase orders provide that they
are “governed[,] interpreted[,] and constructed by, and in
accordance with, the law of the State of Ohio.” Although Styberg
denies that Ohio law governs the entire dispute, it does not
develop its choice-of-law argument and relies almost exclusively
on Ohio law. Accordingly, any dispute about which state’s law
controls is waived. See United States v. Holm, 

, 877
(7th Cir. 2003) (stating that perfunctory and undeveloped
arguments are waived).
6                                               No. 06-4395

    Based on the record, the Court finds that there was
    not a contract. Styberg could not meet and refused to
    accept any of the proposed terms. It needed additional
    money for tooling. It could not meet the monthly
    production targets set in the letter and purchase
    order. It needed to increase the unit price to cover
    design changes. It needed a higher total number of
    unit sales to cover its expenses. Finally, it needed more
    lead time and needed to extend the timetable by nearly
    a year. The parties never came to like terms of any
    kind of agreement. When asked of the Plaintiff to point
    to what constituted the agreement, Plaintiff was not
    able to do so in a manner that even came close in a
    legally satisfactory manner. For a company that did
    business on the written word of contracts, they were
    unable to produce one.
The district court characterized the e-mail, telephone, and
letter exchanges as evidence of continuing negotiations
in which the parties could not agree on key terms like
quantity, price, and monthly production volume. Accord-
ingly, it concluded that the parties never formed a con-
tract. Styberg appeals.


                     II. DISCUSSION
  On appeal, Styberg claims that the district court’s
factual findings and legal conclusions were erroneous, and
that this Court should enter judgment in its favor. We
review the trial court’s determination that no contract
existed for clear error. See Thomas v. Gen. Motors Accep-
tance Corp., 

, 307 (7th Cir. 2002); Teamsters
Local Unions Nos. 75 and 200 v. Barry Trucking, Inc., 

, 1010 (7th Cir. 1999) (recognizing that the
existence of a contract is a mixed question of law and
fact subject to clear error review). Additionally, after a
full bench trial, we may not set aside the district court’s
No. 06-4395                                                 7

findings of fact unless they are clearly erroneous. Cerros v.
Steel Techs., Inc., 

, 1044 (7th Cir. 2002).
Moreover, this Court gives significant deference to the
trial court’s credibility assessments. Id.3
  Ohio Revised Code § 1302.07(A), the state’s codifica-
tion of UCC § 2-204, provides that “a contract for the
sale of goods may be made in any manner sufficient to
show agreement, including conduct by both parties which
recognizes the existence of such a contract.” Courts and
commentators agree that the UCC takes a liberal view
towards what is required to create a contract for the sale
of goods. See, e.g., Architectural Metal Sys., Inc. v. Consol.
Sys., Inc., 

, 1230 (7th Cir. 1995) (recognizing
that the UCC tolerates “a good deal of incompleteness
and even contradiction in offer and acceptance”); WHITE
AND SUMMERS, UNIFORM COMMERCIAL CODE § 1-2 at 4-5
(4th Ed. 1995) (noting that Article 2 of the UCC makes
contracts easier to form by reducing the required formali-
ties); Am. Bronze Corp. v. Streamway Prods., 

, 1299 (Ohio Ct. App. 1982) (recognizing that
§ 1302.07 liberally defines the formation of sales con-
tracts). Notably, however, nothing in the UCC or Ohio’s
code eliminates the requirement that, for a contract to
be enforceable, it “must . . . be specific as to its essential


3
   Styberg argues that less deferential review is appropriate
because the district court completely ignored Ohio’s codifica-
tion of the Uniform Commercial Code (“UCC”). We disagree. The
district court’s written opinion specifically relied on Ohio’s
Commercial Code and cases applying it. For example, the
court cited Alliance Wall Corp. v. Ampat Midwest Corp., 

(Ohio Ct. App. 1994) (applying Ohio’s Commercial
Code) and Energy Marketing Services, Inc. v. Homer Laughlin
China Co., 

(S.D. Ohio 1999) (applying Ohio’s
Commercial Code), in addition to various provisions of the
Ohio statute.
8                                              No. 06-4395

terms, such as the identity of the parties to be bound, the
subject matter of the contract, consideration, a quantity
term, and a price term.” Alligood v. Procter & Gamble Co.,

, 669 (Ohio Ct. App. 1991).
  In this case, Styberg argues that the documentary
evidence conclusively established the existence of a
contract and that the district court erred in finding that
no contract was formed. According to Styberg, the par-
ties agreed that Eaton would purchase 13,000 I-brakes
from Styberg at an average unit price of $544.88. Styberg
identifies three possible sources for the alleged contract:
1) Lisa Fletcher’s July 29, 1999 letter; 2) Baker’s Septem-
ber 9, 1999 schedule; and 3) Eaton’s request for I-brakes
in the Spring of 2000.
   First, Styberg argues that Lisa Fletcher’s July 29 letter
was either an acceptance of Styberg’s July 8 offer to sup-
ply Eaton with 13,000 I-brakes or an offer to purchase I-
brakes that Baker accepted on August 9, 1999 by saying
“thank you.” Then, according to Styberg, although the
parties had a contract with the price and quantity terms
firmly in place, they continued to negotiate about larger
orders and other open terms. Eaton, on the other hand,
characterizes Lisa Fletcher’s letter as part of a series of
ongoing negotiations, during which Eaton and Styberg
could not agree on the essential terms. Eaton claims that
Styberg wanted a commitment for some 20,000 to 60,000
I-brakes in order to justify its capital investment, and
Eaton did not want to be bound by such a large commit-
ment.
  In our view, the district court did not err by concluding
that the communications were ongoing negotiations
about a contract that never came to fruition rather than
an actual contract. Indeed, the court’s decision was
supported by relevant case law, which states that typically,
a price quotation is considered an invitation for an offer,
rather than an offer to form a binding contract. See Dyno
No. 06-4395                                              9

Constr. Co. v. McWane, Inc., 

, 572 (6th Cir.
1999) (applying Ohio law). If Styberg’s July 8 price quota-
tion was not an offer, then the July 29 letter could not
have been an acceptance. Moreover, “it is most often the
buyer’s purchase order, submitted in response to such a
quotation that constitutes the offer.” Babcock & Wilcox Co.
v. Hitachi Am., Ltd. 

, 827 (N.D. Ohio
2005). The parties agree that Lisa Fletcher did not send
Styberg a purchase order for 13,000 I-brakes.
   Even assuming that Fletcher’s letter was an offer in
response to the price quotation, the district court’s find-
ing that Styberg rejected the offer and continued to push
for a higher minimum-unit commitment was a reasonable
interpretation of the evidence. After Baker allegedly
manifested his acceptance by saying “thank you” on
August 9, the two companies participated in a conference
call during which Styberg again indicated that a 13,000
unit commitment was not enough. Baker’s own notes
from the September 1 call state that September 15 was
“ ‘D’ Day agreement,” presumably meaning the parties had
not yet formed a contract on September 1.
  Next, Styberg argues that a contract was formed on
September 27, 1999, when Fletcher told Baker that his
proposed schedule from September 9 was acceptable. We
reject this argument as well. The district court found
that Fletcher never made such a comment, and that
finding was not clearly erroneous. The court emphasized
that Baker’s own notes from September 27 indicated only
that he left a message for Fletcher, suggesting that he
never spoke with her at all. Because the district court’s
conclusion was supported by its assessment of Baker’s
credibility as well as the documentary evidence, we are
in no position to second-guess it.
  Finally, Styberg contends that the parties’ conduct
clearly demonstrated the existence of a contract. We
10                                            No. 06-4395

disagree. The district court found that Eaton’s request
for two 240-unit orders at the price specified in Styberg’s
quotes was insufficient to prove an agreement for the
sale of 13,000 units, and that conclusion was not clearly
erroneous. Although one Ohio court has required a buyer
who accepted $5,500 worth of cable to accept all $35,000
worth of it, the buyer in that case had sent the seller a
purchase order for the full amount, which the seller
accepted by shipping the goods. TLG Elecs, Inc. v.
Newcome Corp., No. 01AP-821, 

, at *3
(Ohio Ct. App. March 5, 2002). Here, by contrast, Eaton
did not submit a purchase order for 13,000 I-brakes, so
accepting the 240-unit shipment did not require it to
accept 13,000.
  Moreover, courts finding contracts based on parties’
conduct have typically done so either where there was
repeated and ongoing conduct manifesting an agree-
ment or where the parties had an established course of
dealing to which they adhered. See, e.g., Central Transp.,
Inc. v. Cleveland Metallurgical Supply Co., No. 63055,

, at *2-3 (Ohio Ct. App. July 15, 1993)
(holding that the parties’ conduct manifested an agree-
ment where the buyer submitted a purchase order, the
seller shipped coal to the buyer on numerous occasions,
the buyer paid for each shipment, and the parties con-
tinued to do business even after a dispute arose between
them); Am. 

(finding a bind-
ing contract was formed where the parties followed their
usual procedures for placing and accepting orders). In
this case, Eaton’s two requests for 240 I-brakes, one of
which was cancelled, did not come close to the repeated,
ongoing dealing that proved a contract in Central Trans-
port, nor did it adhere to the parties usual course of
dealing as in American Bronze. In fact, if the parties
intended to contract, they deviated from their usual
procedure because, historically, Eaton would submit a
specific purchase order to Styberg and Styberg would
No. 06-4395                                                  11

send Eaton a purchase order acknowledgment form.
Therefore, the district court properly could have con-
cluded that Eaton placed the orders pursuant to the
parties’ previous arrangement dating back to 1998 rather
than a new contract for 13,000 units.4
   In short, the district court accepted Eaton’s interpreta-
tion of ambiguous evidence and its choice between two
reasonable interpretations of that evidence was not
clearly erroneous. See Anderson v. Bessemer City, 

, 573 (1985) (stating that clear error review does
not permit an appellate court to reverse merely because
it would have decided the case differently).


                     III. CONCLUSION
  For the foregoing reasons, we AFFIRM the judgment of
the district court.

A true Copy:
       Teste:

                         ________________________________
                         Clerk of the United States Court of
                           Appeals for the Seventh Circuit



4
   Even under a partial-performance theory of liability, Eaton
accepted and paid for the order that Styberg filled, so it met
its obligations. See Ohio Rev. Code § 1302.04 Cmt. 2 (noting
that where partial performance is the basis for finding the
existence of a contract, recovery is limited to the scope of the
performance); Royal Doors, Inc. v. Hamilton-Parker Co., No.
92AP-938, 

, at *5-6 (Ohio Ct. App. April 29,
1993) (same).


                    USCA-02-C-0072—7-9-07