sigh
do you understand how the market works? do you know that the current value of a stock (or in this case, a precious metal such as silver) is based not only on demand right now, but on the expected demand in the future. aka the fact that the current price of silver, already reflects the possibility of the dollar losing its value and that there is "shortage of silver". this means that the price of silver could very likely be inflated.
also, that silver has gone up quite a bit in value recently. buying stocks after a large upswing is historically an awful way to invest.
These two things make the chance for an setback fairly large. Yes silver will always have value, and yes gold has traditionally outpaced inflation (would have to check on silver), but in the short term, this is a fairly risky investment. And in the long term, this is a very defensive/conservative investment
Now if you think that the whole world will collapse and we are going back to the stoneage and a barter system, you should buy some more juice, some rifles, and move somewhere near packs of bison