The price of commodity will fall to the cost of production, yes. That's why commodity producers often form gangs... I mean legitimate trade unions... (OPEC being the best example) But producers find a myriad of ways to de-commodify their goods; trademarkes, patents, and IP law help uphold these "moats" of differentiation... you may know how the recipe to Coca-Cola but you can not sell a soft drink with that name.