This happened quite frequently in eastern Europe during the Jewish Pogrom of the 1930-40s when the ghetto's were setup under the German Nazi Regime. Those with the most Gold and Silver left to trade for food survived the longest before dying of Starvation. Those with a large amounts of Gold where able to trade their gold even for freedom and passage to other neutral countries such as Sweden and Switzerland.

Gold and Silver ownership has its place in the last ditch effort to survive in absolutely barbaric times.

As mentioned in the third world, the means to survival is definitely food, potable water and shelter. The lack of these resources is due to poverty i.e. the lack of enough wealth to purchase such items. If fiat paper currency becomes worthless through devaluation i.e. hyper inflation then the second line means of trade will become Gold and Silver or other precious metals. This has been historically true.

If a bartering system becomes the predominant system of trade, then you may well find yourself going back in time 2000-2500 years. Primitive times indeed and I would have to say even medieval dark age populations densities also!