I believe San Andreas wouldn’t be traded in by GameStop because the original ones had the “hot coffee mod” which allowed a cut scene in which your character had sex with a naked woman. Pretty awesome stuff but caused a lot of trouble with parent groups and the developer
Had to fix the issue and block the mod from being possible on future discs they made.
http://gta.wikia.com/wiki/Hot_Coffee_Modification
“
In mid-June 2005, a file dubbed Hot Coffee was released that modifies
Grand Theft Auto: San Andreas. After installing the patch/mod, users can enter the
protagonist's girlfriends' houses and engage in a crudely rendered, partially clothed sexual intercourse mini-game.
This feature was disabled from the game before release, but not actually removed. This was discovered by several modders in 2004. Patrick W released a modification (the Hot Coffee mod) to enable it. This was made downloadable for the
PCin June 2005 and was released for the
PS2 and
Xbox soon after.”