[ttt333]

If you consider "add to quality of life" a synonym for marginal utility I think you may be in agreement.

Yes, $10 buys the same Mcdonald's lunch regardless of how much money one has, but two people, one with $0 and one with $1bn in net worth will be excited about that lunch to very different degrees.

[giantg2]

"Money also has diminishing marginal utility, so as you accumulate more of it, at some point it has less use."

This thread in response to this, to point out that the use of money is not the same as the marginal utility.