Official XBox 360 Prices
Major Nelson has the scoop over at https://www.majornelson.com/2005/08/17/xbox-360-details-and-prices/.
The "core" package (XBox 360, wired controller, and standard TV
connection) will run $299. If you want all the sweet goodies
(20GB HDD, wireless controller, etc...) then it is going to be $399.