Seems this would be counter-intuitive only in a vacuum; that is to say, were there no such thing as opportunity cost. Perhaps that's what you meant by "utility

Seems this would be counter-intuitive only in a vacuum; that is to say, were there no such thing as opportunity cost. Perhaps that's what you meant by "utility of money" not being linear. And, I agree with that point. Where we differ is that I don't see how you are acknowledging that in only some cases. The degree may change, but not the underlying concept.