It ought to be set up with 2 categories, wants-for-trade and haves-for-trade. Then as a subcategory, there would be TV show titles (which each user could add if it wasn't already in there). Then once the show title was in there, each user could post their wants and haves.

This would avoid neat stuff being bumped into oblivion. Granted, shows would end up having a lot of posts, but at least you could look only at what you're interested in.