Store4PC via Amazon offers Prime members the Sabrent 4-Port Compact USB Wall Charger, model no. AX-UCFW, for $9.99 with free shipping. (Non-members can spend $35 or more to bag free shipping; otherwise, it adds $5.21.) That's $20 off and the lowest total price we could find. It features a 2.1a port and three 1a ports.