Western Digital Caviar 640GB Black Edition SATA Internal Hard Drive for $69.75 shipped after coupon code WDPROMO. The Black Edition has a 5-year warranty and is Western Digital’s high-performance product line of SATA drives that usually require a premium. More information can be found here. Note that it comes in OEM packaging, which means no pretty retail box and marketing materials but is otherwise identical. Others usually sell it for about $84.