hey guys, quick question:

i have a lot of store credit at a local used games/electronics store, but their selection of games is usually pretty underwhelming. right now i'm trying to save up enough credit to get a vita, however they have very rarely had one in stock, and based on the condition i've seen for some of their other handhelds i wouldn't be shocked if it was scratched and nicked.
i've been thinking about maybe getting some games from there, and trading them at best buy; which games should i look for to give me the best trade in value?