Opinions on a reasonable price for xbox360 +?

Okay Im thinking about saleing my xbox and i dont wanna ask to much or to little i want a reasonable price for it. I have xbox360 with 20g. I have two wireless controllers the keyboard for them headset for it as well and then the games to go with it I have cod waw. cod 4 . Cod mw2. cod black ops, older madden game Fable 3. Red dead redemption, first battlefield, and a couple others i cant think of. Reasonable price for it and would selling it on craiglist or selling it to game store be a better option.