Interesting, I looked up metal prices just recently, maybe for the first time ever. That was after I started thinking about the value of housing re: Piketty. My thinking is to downsize drastically and put away several forms of "cash." Here are my convoluted thoughts in the midst of reevaluating the wisdom of holding "wealth" (such as it is) is housing or switching to something else.
I'm pretty sure no one knows what happens in a big US crash. In the great depression the government "bought" up all the gold and made metal illegal to use as money or even to hold as savings. In '08 they used fiat currency as it is designed to be used and increased it's availabilty in order to revive a frozen credit market — yet to know if it was successful or not.
Inflation happens when there are too many dollars because either .gov mishandles things or because the economy is too hot, prices and wages are climbing too rapidly, the economy is expanding from increasing wages chasing too few products. Deflation happens when there are too few dollars because there is too little work, too little demand, too few dollars circulating — doesn't matter how many dollars there are under various mattresses, elevatored garages, offshore accounts, corporate coffers — all that matters is how many are circulating in and out of your hands. In a scenario where the economy is shrinking and people are scared, dollars become more valuable because people hang on to them.
That is the real danger, Weimar was isolated to one country when Germans were forced to make reparations and made to do it in something other than marks, as they traded for other currency (that still had value), the mark fell so they traded more and so it fell further and further. Global deflation will likely be the result of global de-growth, there will be no "other" currency.
Doomers and apocalyptic fantasizers have this idea that metal has some intrinsic value that is immutable. Fact is, when used as a currency it is just like any other, be it paper, sea shells or buffalo chips; it is only worth as much as the parties to the transaction decide it is worth - and therein lies the biggest problem.
Let's say it is the end of the world. You whip out your sack of hoarded pre-64 silver to buy some beans, toss a quarter out on the counter and the kid says, "Sorry, the beans are $5, not 25¢."
Or, you and I both want to buy our neighbor's wheelbarrow to bug-out to the Territories. I whip out a couple of Franklins and you whip out a handful of dimes. Honestly, which is he gonna want? Or you go to the friendly local money changer to redeem some gold for seashells and he tells you that everyone and their brother is selling gold these days so it's value is pretty well nil.
Beyond that, it doesn't make sense to me to buy a commodity at retail and sell it at wholesale, which is what happens buying and selling gold – if you're lucky. If you aren't lucky you buy high and sell low. Metals are a speculative bet, and "traders" bet on every conceivable thing in the world (including other bets) it is hard for me to believe they don't speculate on metals.
The great dollar apocalypse was 1970's thinking after Nixon took the dollar off gold completely. US has "debased" the currency terribly yet the US$ price of gold has fallen by 25% in the last couple of years, that's deflation.

But overall, the value of gold is directly linked to global inflation. If you think the global economy is going to boom and inflation is going to take off then buy gold and sunglasses, if you think something different is going to happen there are probably lots of things that will store value better.

The legitimate object of government, is to do for a community of people, whatever they need to have done, but can not do, at all, or can not, so well do, for themselves -- in their separate, and individual capacities.
-- Abraham Lincoln, Fragment on Government (July 1, 1854)