But that doesn't mean the oil can be shipped to its point of consumption for $10/barrel. When OPEC tries to raise oil prices by cutting production, all they do is sell less oil at the higher price than they would have sold at the lower price. Restricting output in an attempt to raise prices is one of the more idiotic approaches to doing business. If there was a demand for 100,000 widgets in the world and you could produce them for $1 apiece and your competitors could produce them for $2 apiece, why in the world would you produce only 50,000 of them if you are capable of producing all 100,000?
Not all crude oil is equal either. There are different grades. Some takes significantly more refinement than others. So even thought the cost per barrel may be lower the actual cost of making it usable is higher.