As one of its daily deals, 1SaleADay cuts up to 68% off refurbished Western Digital Passport Hard Drives. (Log in and click the "Flash" tab to see these items.) Even better, these items are all eligible for free shipping. With deals from $39.99, that leaves many of these hard drives at the lowest total prices we could find. Deal ends today.

A best bet is the refurbished Western Digital 1TB My Passport Essential Portable USB 3.0 / 2.0 External Hard Drive (pictured), model no. WDBBEP7500ABK, for $67.99 with free shipping. That's $0.07/GB and the lowest total price we could find for a refurb by $7. (It's also $11 below the lowest total price we could find for a new one.) This USB 3.0 hard drive is also USB 2.0-compatible