The commodity is then sold precisely for what it is worth, or for what it really costs the person who brings it to market; for though, in common language, what is called the prime cost of any commodity does not comprehend the profit of the person who is to sell it again, yet, if he sells it at a price which does not allow him the ordinary rate of profit in his neighbourhood, he is evidently a loser by the trade; since, by employing his stock in some other way, he might have made that profit.