How much should i sell my xbox 360 20GB for?

I have the 20GB XBOX 360. I want to sell it for $250-300. Is that to expensive?

I am selling it as a bundle and it comes with the following.

-Xbox system

-20GB Hard Drive, Extra memory chip(Built in I think)

-All cables

-MW2

-GTA IV

-Dragon Age II

-Assassins Creed II

- Assassins Creed II Bonus content disk

-Your in the movies

-Xbox vision camera

-Enslaved:Odyssey to the west

-Madden '09 Demo

-Harry Potter: And the Sorcerer's Stone

-2 Controllers

-3 Rechargeable battery packsHow much should i sell my xbox 360 20GB for?
more than that, with all those games and accessories, try 400-500How much should i sell my xbox 360 20GB for?
Thanks adam. But do you really think that much? BTW THIS IS MY OTHER YAHOO ACOUNT. And where do i sell it for that much?