Ocean Technology via Amazon offers the Unitek USB 3.0 3-Port Hub and Docking Station for $21.89. Coupon code "TGX6TG5V" cuts that to $7.99. Plus, Prime members bag free shipping. That's the lowest price we could find by $18. It transforms Windows tablets, Android devices, and Ultrabooks into a desktop PC and features Gigabit Ethernet and three USB ports for peripheral devices. Deal ends August 15.