Dell Small Business & Home Office offers the Clickfree C2 500GB Portable USB 3.0 2.5" External Hard Drive, model no. CA3A05-2CBK9-F1S, for $69.99 with free shipping ($0.14/GB). That's the lowest total price we could find by $16. Sales tax is added where applicable. It can be used to automatically backup Windows or Mac computers and features a transfer rate of 640 MBps.