From my experience in cycling, I quickly learned that a bike shop will take an el cheapo item, put a picture of a bike on it and triple the price.
I've seen the same thing in outdoor gear too. Walmart sells a trowel for under $5 that REI sells for $16. I bought neither one since sticks are free and I have an extra tent stake.
I understand that my experience as a weekend and short trip backpacker doesn't fully qualify me to evaluate gear for the long haul. I've seen though, through trail and error, some of the things where I needed/wanted to spend some dough - almost anything with down or wool, a lightweight tent, Osprey packs, I've also used a few things from Walmart that seem to be cheaper and as functional as need be: grease pot, HEET, butane gas, wool socks, synthetic base layers (which will end up smelly but are cheap enough to replace), a beanie/skullcap/tuque, a head lamp. My question is - what other things could you good folks suggest I get at Walmart (or other discount) store?