Gold & Silver have their prices manipulated to show price volatility. Those manipulating prices position themselves to profit from that price volatility.
The true value as compared to Dollars in circulation was recently added to the following page. Note that they are in the bottom-right corner of the page.
http://usdebtclock.org
Values of these precious metals are stable, but not their price in fiat currency. The value is as compared to other commodities, not to a particular currency.
When food and other necessities become difficult to acquire, the first thing is that the price goes up. Typically, the value of the fiat currency goes down at the same time, and the important things are VERY EXPENSIVE. This typically happens well before there being Nothing to buy with what you have saved.
I remember a scene from "It's a Wonderful Life" where the main character just happened to possess a significant amount of the fiat currency at a time when the bank failed. He was able to essentially save the town from ruin (complete ownership by a corrupt entity) and made a significant difference in the lives of the people. Even that paper had some value in bad times.
I like land, etc., as an investment, but that has its own problems. Prices there are volatile, and associated taxes are attached to the ownership of land. Great lands are often sold off (or partially deeded to the taxing authority) to settle tax debt. Huge lands end up being much smaller because of this, and may eventually be completely removed from the hands of the owners.