Last week, Microsoft confirmed rumors that the Xbox 360 would start supporting USB flash drives starting April 6. The move came after nearly four and a half years of Microsoft only offering first-party proprietary memory units and hard drives, which were widely criticized for being overpriced. It also came just over four months after Microsoft locked out high-capacity third-party memory units with a fall firmware update.

SanDisk's Xbox 360-branded 16GB USB drives cost twice as much as the unbranded ones.

As part of the USB-support announcement, Microsoft said that it was partnering with SanDisk to release Xbox 360-branded USB flash drives. Now, GameStop is listing the official USB drives, which bear a higher price than un-branded third-party devices, for preorder. The 8GB drive retails for $39.99, while the 16GB model sells for $69.90. By comparison, an unbranded SanDisk 16GB thumb drive is on sale on Amazon for $28.50, or 59 percent cheaper.

According to the GameStop description, the main selling point of the Xbox 360-branded USB flash drives is that they are "preconfigured" for a "seamless experience" and come with a one-month Xbox Live Gold membership, which has a full retail value of $8 but can be acquired for as much as $2.50. However, formatting an unbranded third-party drive is as easy as plugging it into the Xbox 360, going to the system settings area, selecting the USB device, and selecting "configure now."