Xbox 360's 500 GB HD is cheaper than its 320 GB cousin but still expensive (update)

You'll soon have the option to upgrade your Xbox 360 with a 500 GB hard drive for $109.99, according to a product listing on the official Xbox website.

Pre-orders for the device are "coming soon," and you can check out an image of the upcoming product below. The Xbox 360 is currently available in 4 GB and 250 GB configurations. The Xbox One ships with a 500 GB internal drive and support for external storage, while a Call of Duty: Advanced Warfare model set for a Nov. 3 release will include a 1 terabyte hard drive.

Microsoft's hard drives are the only officially sanctioned way to upgrade the storage in an Xbox 360, and the prices trend higher than naked 500 GB hard drives, which sell for around $50 on Amazon, New Egg and other retailers. Microsoft sells a 320 GB Xbox 360 hard drive, compatible with the Xbox 360 S and Xbox 360 E models, for $129.99.  We've contacted Microsoft for more information on the future of that product and will update this article as we receive it.

Update: A Microsoft representative told Polygon that the 320 GB hard drive is being discontinued.

"The Xbox 360 320 GB media hard drive will be available while supplies last," the representative said. "We are offering the new Xbox 360 500 GB media hard drive as an option for users looking to upgrade their external storage for Xbox 360.

"We are working with retailers to revise pricing on the Xbox 360 320 GB media hard drive to maintain market competitiveness, as we do on a regular basis."