XIGMATEK Secure III USB 3.0 Hard Drive Dock for $20 + free shipping
newegg offers the XIGMATEK Secure III USB 3.0 Hard Drive Dock in White, model no. CPH-SPHET-U07, for $19.99 with free shipping. That's the lowest total price we could find by $18, although we saw it for $2 less last month. This USB 3.0 docking station connects 2.5" or 3.5" SATA hard drives to a Mac or PC and features hot-swappable bays. It's USB 2.0 compatible.
Of note, newegg incorrectly states the model number as CPH-SPHET-U08 in the headline; it should be CPH-SPHET-U07.