But that's not the same thing, value is by definition subjective, and price does not express my valuation or your valuation of the items traded, it just express

But that's not the same thing, value is by definition subjective, and price does not express my valuation or your valuation of the items traded, it just expresses the intersection of supply/demand curve. Value provided by antibiotics is enormous and yet antibiotics are cheap. If we created a law saying that I have a legal monopoly on all antibiotics sales for the next 20 years, the price of antibiotics would go up but it's value/utility wouldn't have to change - we don't need to quantify that statement to evaluate it. It's still very high on your marginal utility list, so you pay more. And the GDP was "increased" (assuming the money spent was from savings/loan that wouldn't be spent in the time measured otherwise) but you aren't any richer, only the producer is, and he got rewarded for monopolistic pricing. Profit is a good incentive when the producer corrected the resource allocation to take capital to a more productive use under the market rules, but it can be perverted if you don't have competition putting pressure, have rent seeking or don't account for negative externalities.