Okay, I am pretty sure that Alien isn't going to like this response, but so be it.
#1. The contest ended and it was not the fault of either you or Rick. Rules were set, they were not met. Shit happens.
#2. Rick may be offering outsourcing design, but IMHO, the people using his service probably are not really your target demographic anyway.
#3. I don't think you have the ability to bring him down even if you spent every waking hour trying to accomplish it. Trying to do so would be an exercise in futility, and the time would be better spent making $10k on your own.
#4. I think Rick's offer seems rather fair, however, my years of negotiation have taught me that negotiations boil down to demand and offer, counter-demand and counter-offer. Unfortunately, you kind of blew that when you stated you would not even accept the $10k (should it even be on the table).
#5. If you were asking for my advice (which I don't think you are), I would probably tell you to accept his offer (or try to bump it a little
) then meet with him at a show. With your skills I think it is possible that you could enter into a great business relationship with him. I know that if I could do business with him, I would likely jump at the opportunity.
The cliche' of cutting your nose to spite your face seems to be appropriate in this matter. If you would like me to attempt to negotiate a solution to this, I would be more than happy to. My fee is 20%.