mwave offers the refurbished Western Digital RE2 400GB Serial ATA 3Gb/s 3.5″ Internal Hard Drive, model no. WD4000YS, for $49.95 with free shipping ($0.12/GB). That’s the lowest total price we could find by $63. (We’ve seen larger hard drives for less, but not since last fall.) This drive runs at 7200 rpm and features a 16MB cache.
Note: A 60-day warranty applies, although it’s unclear who backs it.