I never sell my games voluntarily. That's that. Once I own it, you have to pry it from my dead body! Hahahahaha!
That said, assuming you don't have rare games like Xenoblade, you'll almost never get good prices for your game.
I WON A BET AGAINST AZUREN! WOOOOOOOOOOAAAAAAAAHHHHHHHHHHHHHHHHHHH
:3