BuyDig via eBay offers the Western Digital 3TB My Passport USB 3.0 Portable Hard Drive in four colors (Berry pictured), model no. WDBBKD0030BBK-NESN, for $129.99 with free shipping. That's the lowest total price we could find by $19. This drive is Windows and Mac compatible and features a 5Gb/s maximum data transfer rate.
Update: Specs corrected