Money is life energy.
The real cost of money is the life energy (time and effort) we put towards making it. This is a core principle in Your Money or Your Life.
henry david thoreau though the same but applied it to all—both things and activities. He said:
the cost of a thing is the amount of what I will call life which is required to be exchange for it, immediately or in the long run.
Thoreau did not simply preached a rejection of economic excesses. He advocated that each of us calculate the exact amoung of pure living we are compromising because of money, possessions, and luxury.
Gros, F. (2014). A Philosophy of Walking. Verso.
What impresses is the form of the argument. For Thoreau’s obsession with calculation runs deep. He does not say: let us reject economic weighing of quantities in favour of a pure idea of quality. He says: keep calculating, keep weighing. What exactly do I gain, or lose? What do I lose in pure living when I strive to earn more money? What it costs rich people to be rich, working, worrying, watching, never letting go.