I don't believe the scenario entails a total collapse, but more a rather aggressive inflationary spike, followed by a relative shortage of regular commodities. Most certainly not a catastrophic event that would reduce society to such anarchy that the supply system would have collapsed.

Under such a limited pretext, I would think gold to be a superior tender to state currency or bulk commodities like food. There may be some localized needs that would warrant a bartering system, but by and large, the infrastructure of the country is going to remain intact, it will just get very expensive to transact, and a more stable and universal tender could put a person at an advantage, depending on the scale of their acquisitions and their logistics. This is based on the premise of the scenario under discussion. If it foments into something more egregious, then certainly things such as food, fuel and ammunition become a much more desirable exchange media, but widespread breakdown of regulatory control would pre-empt such activity on anything but a very localized occurence.

If I see mobs looting the stores and gas stations aflame, I'll have already traded my gold off for another heavy metal, cast lead in copper jackets, heh heh heh.