Yeah, Ive thought about that. 90% of these games I bought brand new for $65. I figure i might aswell trade them in though, all they do is collect dust.
like anything else ya buy, trade in values drop for a few reasons (time since the game came out, how many of that particular title have allready been traded in) when a new game is traded in, initially the value is usually half what it cost (i.e. a $50 game trades in for 25-30) as time passes the trade value drops, another factor is if the game , well, sucked lol, those usually don't trade in well either