Prices pay the cost of inputs.
The inputs of a business are labour, materials, and capital.
A wage pays the support, training, risk, and trust costs of labour.
And if that wage falls below those costs, then labour cannot be sustained.
Given numerous market and power asymmetries, it's often possible to impose lower-than-living wages by shifting risks and costs to labour.
A man must always live by his work, and his wages must at least be sufficient to maintain him. They must even upon most occasions be somewhat more, otherwise it would be impossible for him to bring up a family, and the race of such workmen could not last beyond the first generation.
Adam Smith actually writes on this extensively in Wealth of Nations, with insights that remain valid over 240 years later. Which answers your initial question.
See: https://news.ycombinator.com/item?id=26127620
https://en.wikisource.org/wiki/The_Wealth_of_Nations/
http://oll.libertyfund.org/titles/smith-an-inquiry-into-the-...