"""In a normal competitive market, prices will be set by the cost of producing an extra barrel from the cheapest oilfields with spare capacity.""" This seems w

"""In a normal competitive market, prices will be set by the cost of producing an extra barrel from the cheapest oilfields with spare capacity.""" This seems wrong as the marginal price is determined by the utility of an extra barrel of oil for the consumer not by production cost. Sounds like a fall back to the labor theory of value (aka classical economics and/or Marxism) to me.