Sunvalleytek via Amazon offers Prime members the RAVPower 3.4-amp 17-watt 2-Port USB Travel Wall Charger in White or Black, model no. RP-UC05, for $5.99 with free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $6.98.) That's $3 below our February mention and the lowest total price we've seen. (Outside of the deal below, it's also the best price we could find for a 17-watt dual USB wall charger by $4.) It features 2.4-amp and 1-amp ports.
A close price for a similar device, PowerGen via Amazon offers Prime members its PowerGen 3.4-Amp 17-watt Dual USB Wall Charger in White, model no. PGAC17W-WH, for $6.99 with free shipping. (Shipping costs $6.10 for non-members.)