Get a modded console. Right now they're $30 NZD pre-owned where i live, so they're really cheap and probably will cost less than buying the drive itself. (ofcourse you'll have to mod it yourself unless you buy it modded-softmodding is the best way to go if your not looking to buy a modchip or for a easy solderless solution)
You get the benefits of backing up games and playing them on your xbox