AnkerDirect via eBay offers its Anker PowerHouse 120,000mAh Portable Outlet for $499.99. In cart, that falls to $349.99. With free shipping, that's by far the best price we've seen for this model and $50 under what Amazon charges. Features include a 12V car socket, 110V AC outlet, and four USB ports.
In the gig economy, baby boomers are out-hustling their younger competition. You can cash in, too.