At a local small town second-hand retailer I saw an expedition sized backpack for 20 dollars, with a main compartment you could almost stuff a dead body in if you throw away the head, arms, and legs. The tag said it was only used once so I would only have to ask a few questions to get the details.

Thinking about getting it but still not sure if it's something I need, as I am still playing with my frame pack, and still carrying my butt pack most of the time, which is stuffed to capacity.