The disk (WDE1MS1200) is $89.10 (online price) at Harris Technology. You can pick it up or have it delivered at a low fee. The price is even better than those of no-name USB hard disks from Chinese/Hongkong vendors on eBay.
You can get 4.5% back through MonneybackCo.
Hmmm… I wonder if you can stack this with HT's "10% cashback for Paypal users" deal, which starts tomorrow?