But no, read what I wrote carefully. I said that WalMart DOES understand market value -- better than you or I.
But they don't just sell ammo. They sell 100,000 other products, and they have a market strategy that says they DON'T follow the market when one of their items goes through a market value swing. Their theory is that they want to be known for LOW prices. So they'll sell some things for much less than they could get for them -- i.e.: what the market is valuing them at. Even less than is profitable, occasionally. That gets butts in the store. They DON'T care that there aren't any of that item on the shelf today. People will still come look and while they're there they'll pick up some shampoo, a gallon of milk, a DVD and a t-shirt. The strategy is GOOD for WalMart, but not really good for "the market" as a whole. For one thing, it make all the other retailers (your beloved local gun shop, for example) look like cheats when they push their prices up to meet demand (and costs). For another, it simply FORCES the creation of a "flipper" class of folks who will trade their time standing in line at 6:00 am for making a clear $20-30 a brick on .22s. The product is selling at WalMart so far below what the collection of buyers is willing to pay for it, that someone is going to step in and act as a middleman to reap the harvest of that price discrepancy. It HAS to happen. Expecting it not to is like seeing a large gold brick to fall out of the sky and land in the middle of Main St. and believing that no one will stop to pick it up. It is there for the taking. We're living creatures, we collect resources to extend and better our lives, wherever we can find them. It's part of the definition of being alive.
Buying something for one price and selling it again at a much higher price will always be called greed by someone. Others will call it "making a living" or "wise investment" or some other term. If the point of the exercise is to turn a profit and therefore continue to meet life's expenses and maybe get ahead, then "greed" is absolutely fine, positive, and necessary.