Well, you're actually proceeding from an incorrect assumption: money is nothing more than a medium of exchange--the true value of all goods, services and commodities is actually the energy contained therein. That's never more apparent than with food. If you don't take in enough calories, you'll essentially waste away and then die a diseased death as your immune system will shut down before allowing the brain and other core organs to go.
Anyhow, the core of any economy is based on manufacturing, farming or harvesting resources that others want or need. The US is currently importing roughly 2/3rds of its liquid fuels (crude oil and the like). Oil, gas and coal are the true workhorses of all of today's economies and historically the more we've drilled or mined, the more energy we've had to get even more, thus increasing our available energy capacity exponentially. That is, right up until recently. For awhile now, the EROEI (Energy Return On Energy Investment) has been decreasing even as the consumer base has been exponentially INcreasing (and on a worldwide basis, too).
We've been working hard these last few decades on increasing efficiencies, but there eventually comes a limit that makes it uneconomic to pursue efficiency further in any such endeavor. Oh, yes, we keep hearing about fantastic new energy devices and such, many of which keep getting posted on here. The bulk of them are well and truly "pie-in-the-sky" kinds of things, though. That is, their economics don't pan out nearly as well as oil, coal and gas did--that IS the problem.
We're "going green" whether we like it or not, but the most likely scenario of all this "going green" is that an awful lot of folks are going to be going back to The Little House on the Prairie kicking and screaming. Me, I don't mind, I'm okay with it--I don't much have a need of all this crap anymore, never did. Don't get me wrong, I appreciate it and am a pretty decent innovator within my technical fields. I LIKE cooking and heating with gas. I LIKE electric lights. But I HAVE milked the ol' cow every morning and bucked hay in my youth (a LOT of hay). When I look around at a lot of the agriculturally-challenged city folk today, I can well and truly imagine how bad the descent into the Olduvai Gorge is going to be.
Anyhow, as Peak Oil approaches (we've ALREADY passed the peak of production for RCO, or "Regular Conventional Oil") for All Liquids, it's going to get downright ugly. What you will find is that "money" will begin to revalue on an exponential. That's essentially what happened right up to the peak in price back in July of '08--none of the oil producers could squeeze out another drop fast enough. I know, I know... "d@mn speculators!". Oil's sold essentially in a kind of auction--if there's more demand than supply, the cost IS going to go up. H3LL... the price STAYING up as high as it has been through the last year is almost as bad as that year if you integrate it. Longer term crude futures contracts are already selling for enough to knock your socks off, just wait until that time comes--it's going to continue doing damage.
Once upon a time... you actually used your own muscle powered by the food you ate to get stuff done. Now, you're using an immense amount of power from industrial sources with very little of your own calories by comparison. I suppose you could say the real problem is the amount of debt that a diminishing energy supply is juxtaposed against.
