So he gave the suit away on the condition that the guy had no money. If the guy makes it to MFF, then he must have money, therefore the contract in Rex's head is rendered void. This is probably one of the most fantastic examples of furry economic law I have ever seen.
If you can see that suit at MFF, if this suit is anywhere you have the opportunity to see it, then clearly someone needs to be dragged into the street and shot right along with Rex. Call up CNN, tell them WE ARE NICE PEOPLE BUT THIS IS WHAT HAPPENS.