Comment by Joker_vD

> costs do not have a causative relationship to prices. Prices only go down because as the cost of production goes down, supply increases.

Um. That's a causative relationship, even if it's mediated, but it's still causative. And generally, the relationship is even more direct: the suppliers are quite reluctant to sell at the price lower than their costs unless they expect the prices go up soon enough™, so the lower boundaries for the prices exist.