E Depot Express via Amazon offers Prime members the Etronic 2-Port USB 2.1-amp 12-watt Car Charger (pictured) for $4.44 with free shipping. (Non-members can spend $25 or more to qualify for free shipping; otherwise, shipping costs $5.06.) That's $6 under the lowest total price we could find for a comparable charger sold elsewhere. This device features one 2.1-amp port (for iPads or other such device) and one 1-amp port.

E Depot Express via Amazon also offers Prime members the Etronic 4-Port USB 2.1-amp 10-watt Wall Charger for $7.44 with free shipping. (Shipping adds $5.18 for non members.) That's $2 less than the lowest total price we could find for a comparable item elsewhere. It features four USB ports and a max output of 2.1 amps.