>Whether you agree to buy or sell at a certain price is entirely dependent on whether such price is higher or lower than the value of the trade, in your own subjective assessment.

The subjective assessment of the "value of the trade" is then a function of the subject's alternatives, which is usually how much someone else will pay or accept from them.

I find the term utility to be more beneficial than value, due to it being less likely to be confused. As a boss, I would say I value all the employees equally, in human terms. But the employees provide different amounts of utility/$. Although I can see how people use value and utility interchangeably.

> The subjective assessment of the "value of the trade" is then a function of the subject's alternatives, which is usually how much someone else will pay or accept from them.

I agree that it is a function of the alternatives, but the operative alternative here is not trading. The best way to assess value is that which you lose by taking something away, like taking a player out of a team or a customer out of your book of business