Why would there need to be negotiation? Suppliers offer a price and consumers take it or leave it. Supply and demand causes the price to be set where both producers and consumers are satisfied. Of course the price does not, in itself, bring value. That's not at all what I'm saying. I'm saying that the value is implied by the price. No consumer would buy it unless they perceive that the value is greater than or equal to the price. So, the fact that they buy it tells us that the value is at least as high as the price.