(note: I honestly believe this, but I am presenting it more forcefully than I believe for socratic and exploration reasons).
Interesting. What other approach makes sense? When you stop treating currency as special, all costs are opportunity costs. The only actual loss you experience from spending now is that you can't spend it later.
Well, to start with the Z$ example, you say
your loss (as measured by the amount of Zw$ you could have had later for that USD) was near-infinite
but if everything is just a tradeable good, why do you choose to measure your loss in Z$? Your loss in McDonald's hamburgers is zero, your loss in some now-out-of-fashion accessory is actually a gain, etc. etc. If you don't have money, you have no baseline but just a huge matrix of barter ratios. Whether you have a gain or loss (and its magnitude) solely depends on which pair you pick and there is no pair that's...
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.