What should I sell my X-Box for?

I'm selling it with a 20 gig hard-drive and 18 games. The games are: Blazing angels: Squadrons of WW2, NBA 2K6, Lost Odyssey, M Effect, Samurai Warriors 2 Empires, Call Of Duty: modern Warfare, Farcry Predator, Section 8, Perfect Dark Zero Limited Collectors Editions, Avatar, Rainbow 6 Vegas, Rainbow 6 Vegas 2, N3 Ninety-Nine Nights, Fallout 3, Halo 3, Lord Of the Rings Conquest, The Elder Scrolls 4 Oblivion, and Resident Evil 5.