Best Price Marketplace via Amazon offers Prime members the CyberPower 160-watt Slim-Line Mobile Power Inverter, model no. CPS160SU, for $8.49 with free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, it adds $5.74.) That's a buck under our mention from September and the best price we've seen. (It's also a current price low by $37, outside the price below.) It features a 120-volt AC outlet and USB port.
A close price: A4C offers it for $9.95 with free shipping.