Let's for the moment assume that the absolute worst case scenario occurs, a complete and total economic meltdown. What is someone going to do with gold, silver or platinum coins or bullion? What practical purpose does it serve in a "survival" situation?
As I understand it, it's intended more as a hedge against inflation. There are scenarios where value stored in dollars or pounds becomes virtually worthless, but value stored in gold or silver holds. The reason being, the government can't print more gold as easily as it can print paper money.
I think to make a difference the amount you'd stockpile would have to be quite large - at least 10s of thousands of dollars, rather than 100 dollars here or there.
Whether hyperinflation counts as a "survival scenario" in the terms of this forum is another matter. At this level of collapse there's the economy is still working, just not very well.