Righto, i've decided that i am sick of console gaming, and I am just going to move to PC gaming. Fullstop. Sooo, I'm asking you kind lovely people what i should do in the way of computer. I play a bit of cod on the ol' xbox and i play WoW Lol and css and dods and stuff, but obviously i need an upgrade, im running on a thing i picked up of trade for next to nothing. What kinda price am i looking at, and how much can i sell my Xbox 360 for? 

A month and a half old Xbox 360s 250gb in original box.
A wireless controller
A wired Controller
Call Of Duty MW2
Skate 3
Mass Effect
Halo Reach
Fable 3
Halo 3 odst
Fifa 09