Unlike Gil, I never saw Marx's law of value as a theory of prices being
determined by labor values (even a 95% approximation theory). Volume 1
talks about value all over the place and explicitly abstracts from
departures of production prices from labor-time values. The law of value
is concerned fundamentally with determining the basis of capitalist
exploitation in the exploitation of labor power resulting from the
difference between labor time put in by workers and the value of their
labor power on the market.
Paul Zarembka, SUNY at Buffalo