Value is what people are willing to pay but that is not what should primarily determine prices, they should be primarily determined by the costs of production.

Value is what people are willing to pay but that is not what should primarily determine prices, they should be primarily determined by the costs of production. That is what competition is for, driving the profits to zero and the prices towards production costs. The value of water is very high, people would pay any price because otherwise they would die of thirst. The price on the other hand is low because the costs of production are low. The explanation why the price reflect the costs and not the value in this case, you can pick on your own, maybe competition, maybe the expectation of people with pitchforks if you try to get rich by selling water for $100 per liter, maybe regulations, ... probably a combination of several things.