That's a twisted and myopic logic. You've gone from net value and cost to society, which have broad definitions, and then in the next sentences equated both strictly to money.
Free market prices are a valuation of costs to society. It's the valuation that produces the best results. Humanity doesn't knows a better one.
Twisted and myope logic is the concepts of price and value that socialists have. That's why socialism always fail: socialist don't understand the value of things.
The proof is the experimental results: life is always better in capitalist countries, and socialist always escape from socialism towards capitalism. Even socialists don't want to migrate to cuba or Venezuela.
Marxism is twisted and myope because Marxist define Marxism as the rejection of logic. Your Marxist posture is incompatible with reason.