Marketers are constantly trying to determine the price at which consumers will stop buying, and although usually this is done with surveys, market studies and computer models, the only sure way is to just raise the price until consumption starts to level off. The idea isn't to maximize sales volume or price, but to maximize the product sales x price. Other factors figure in too, like production and transportation costs and economies of scale, but this is the main one.

Normally, you can't do this because some clever competitor will just lower his price to just undercut yours and steal your customers. But during times of scarcity or high demand, or both, it just happens. It isn't because of an evil conspiracy of price fixers or speculators (although I'm sure that happens too), it just that this is how markets work. They teach you this sort of thing in MBA school.

When the supply/demand crisis is over, the seller now has the market data he needs to engineer his price structure so profit is maximized. As the number of major producers falls, and the proportion of production they control increases, it becomes easier for this kind of information to circulate through the market place. It also becomes harder for a small individual producer to compete with that price structure by simply lowering the price, any shift from that price will merely move him into a place where he is less profitable. The small producer simply can't sell enough at the lower price to interfere with the big producers at their higher price.

Adam Smith figured out that this happened a long time ago, Karl Marx determined how and why. Unfortunately, neither of them came up with a solution of how to use this natural force to stretch out an unrenewable resource for as long as possible, or to use it as efficiently as can be.