Fry's offers the Ontrion LifeCHARGE 16,800mAh Portable Power Bank, model no. ONT-PWR-35607, for $29.99 with free shipping. That's $40 under the lowest total price we could find for any 16,800mAh portable power bank elsewhere. It features an LCD indicator, LED flashlight, and two USB ports.
If you know where to look, you can score freebies at the dollar store regularly.