Newegg offers the Zalman USB 3.0 External 2.5" Serial ATA Hard Drive Enclosure in Silver, model no. ZM-VE300-SE, for $20.99 via the directions below. With free shipping, that's the lowest total price we could find by $23. It features a maximum transfer rates of up to 5Gbps and one-touch backup. Deal ends August 25. To get this deal:

1. View the Zalman USB 3.0 External 2.5" Serial ATA Hard Drive Enclosure for $39.99
2. apply coupon code "VCO" and use Visa Checkout to cut that to $35.99
3. redeem this $15 mail-in rebate for a final price of $20.99