This link from Mercurty News has been floating around that points to the official pricing of the upcoming Xbox 360 console.  MS even has the official PR on their website.

The company will sell a high-end Xbox 360 model that will come with  a standard 20-gigabyte hard disk drive for $399. This box will be backward-compatible with the top-selling original Xbox titles and will come with a wireless game controller, a built-in Media Center Extender, a wireless remote control, and an Xbox Live headset. This version will be for the enthusiasts and the hard drive will come with DVD and music content preloaded.

For those who don’t want to pay more, Microsoft will also sell an Xbox 360 core version without the hard disk drive. This version will have a wired controller and it will not have the head set, or the wireless TV remote. Players who buy this version will have to buy flash memory cards to store game data.