How much should i sell my ps3 for?

i want to sell my ps3 with 2 controllers and 8 games: Fifa soccer 11, batman arkham asylum, saints row 2 , god of war 1 and 2,call of duty black ops, uncharted drakes fortune, and call of duty modern warfer 2. is a ps3 slim with 120 gigs how much should i sell it for????? i need answers ASAP :)