Robert Murphy, Choice, Cooperation, Enterprise, and Human Action, p112.

Economic calculation, by its very nature, can attach monetary values only to those elements of our lives that are sold against money. Many things are quite valuable subjectively but do not enter the market nexus directly and consequently cannot be quantified in dollars and cents. Nonetheless, economic calculation is still an indispensable mental tool of action because it shows individuals – with as much precision as possible, given the nature of the situation – the monetary implications of various possible choices. This makes it possible for the individuals to focus their attention on the tradeoffs involved between the monetary and nonmonetary elements of their decision.