The relative fiat-money-value of two tangible goods is independent of the value of the fiat money and is a meaningful quantity. But you are right that converting everything to its fiat-money value can lead to counterintuitive conclusions. I am thinking that changing the numeraire (see my comment to DoDo in a parallel thread) would be a useful exercise to determine whether a value is real or an artifact of fiat money.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman