Yeah, the price point he mentioned was $99... I like the idea, but I'm kinda with you; would I really use it enough to justify the cost? Probably not.. but I'd buy it anywayz..
When I'm going to be in a situation where I know I won't be near a charging source, I carry the original Zagg Sparq, which is also somewhere around 5600mAh (I forget exactly) and can power two usb ports simultaneously. They sell it for $100, too, but Zagg runs frequent sales and offers regular discounts if you follow them on Facebook. I paid $50 for mine.