How much should I sell my psp for on ebay?

I'm selling a psp which is downgraded, 11 UMD games, 11 Movies, earphones, power adapter, skin, UMD case, PSP Manager, USB cable and car charger. Also there are 3 games on the memory stick which are both GTA games and Gangs of London. Some of my friends say about $600. But I got all of this stuff over $1100.