I think that the words price, wage, rate, cost, expense, income, sales, purchases, etc may all denote the same thing from different perspectives. Price is used

I think that the words price, wage, rate, cost, expense, income, sales, purchases, etc may all denote the same thing from different perspectives. Price is used when are interested mainly in the amount especially with respect to other things. So if a programming firm contracts with a client to do work, the contract may talk in terms of the generic price. But the individual programmers doing the work think in terms of wages. And those wages may be a cost or expense to the firm's owners, who also think in terms of rates, income, and sales while the client considers the programming as a purchase. The term price in particular emphasizes the fact that there are options as to how to spend money. For example, a auto company can hire workers directly, in which case it pays wages. Or it can outsource, paying another company a rate for the labor, or it can just buy the finished parts. It makes sense to compare the different options as prices. Certainly wages are considered as prices when it comes to automation decisions. What is price of wages and associated expense versus the price of the robot? This (treating wages as prices) seems like such a basic concept that the burden is on the person who wants to treat wages as different from prices to explain why wages are or should be different.