You won't find any different situation with any other lawyer. Lawyers get paid for their TIME, not their results. If the lawyer wants to take your case on a contingency fee basis, then he gets paid for his results. It's the lawyer's choice as to whether he wants to offer you this type of arrangement. It seems as though this lawyer wants to be paid by the hour. Either pay this lawyer by the hour or go and try and find another one who will take your case on a contingency fee basis. 90 days to make your claim is plenty of time. You haven't been prejudiced at all. Either move or don't.
Best of luck.
