[scheff]

I see money as a measure of value.

The exchange of butter for chickens, and determining what exchange rate would be satisfactory for both parties, quite often does not take into account the effort, or cost, of producing the goods. Say it costs the butter producer 5 years of raising a cow, including the cost of grain and water, and also the processing costs, in the total cost of producing butter. Say it costs 6 months of very little grain and water to raise a chicken. Should the exchange rate reflect the "costs incurred" for production?

A market determines the value of these goods, as defined by the demand. That market value is explicitly defined by monetary value. In this view, money is simply a digital representation of the value of goods and services, allowing consumers and producers to more easily draw comparisons.

In many societies, a job in social services is valued much lower than say a job in IT. The effort involved might be identical, but the market determines the value of the occupation.