Since you said "economic value" specifically, I'd have to say that the man-hours are only one of the factors that could determine value. Strictly speaking, econ

Since you said "economic value" specifically, I'd have to say that the man-hours are only one of the factors that could determine value. Strictly speaking, economic value is determined by supply and demand. Man-hours are a cost and help determine the shape and position of the supply curve of a given good or service, but the demand side is almost completely independent of how much effort it takes to produce something. Instead the demand curve will be shaped the culmination of individuals' marginal utilities (the perceived value of the next additional unit of a thing) for the good or service in question. On a more philosophical note, value is entirely subjective, but the equilibrium price model is compatible with value's subjectivity and gives us a powerful paradigm for understanding why some things are more "valuable" than others