I don't know about caching precious metals against the possibility of TEOTWAWKI. In a complete, world-wide breakdown of governments and economies, most people will be reduced to subsistence level, which means the market (if you can call it that) will be driven by commodities that aid subsistence - food, water, clothing, tools, seeds, etc. Starving people can't eat silver. For silver to have "value," there must be people who have extra food, etc., to trade for it. I'd rather have the food.

Anyone read the book "Alas, Babylon" as a kid? In that TEOTWAWKI scenario, the beekeeper who had honey to trade was way ahead of the guy with a chest full of gold and jewels. A pound of sugar might be worth a lot more than a pound of gold in such a world.