How much should i sell this for?

I got an xbox 360 that is like new because my xbox broke 4 times and i got a brand new one Date: June 28, 2008. I have used it for a few hours but not much. It comes with Kamo,madden 09, madden 07,quake 4,blitz the league,viva pinata,halo 3,civil war, and bioshock. It also comes with rock band full kit(mic,drums,guitar) it also comes with guitar hero 3, with guitar, and guitar hero 2. How much you think this is all worth? Only one controller btw, also hard drive (20gb)