The market doesn't give a fu€k about the cost of production. Years of being in production agriculture is my source. You'd laugh if you saw how insignificant the farm programs are. Now it is simply a subsidy on the purchase of crop insurance. That's it.
Oil industry can steer the price. It's not the only driving factor, but it cannot be considered insignificant. The problem is one part Saudis don't like losing market share to us and Russia and one part your president pissed of the Saudis by chilling with their enemies.