Your definition of SHTF is an important consideration. sounds like your describing a world completly void of governmental rule and standardization. IMO in a coutry as developed as ours if it did get that bad it would be very temporary. Even in that situation you would need a medium of exchange though. Otherwise if you need a pair of shoes but do not have anything the guy selling shoes needs you would have to run all over town trying to transact trades to get your hands on what the shoe salesman wants. If he is willing to accept a certain medium of exchange like silver then you can give him the silver for the shoes and he can use it to go get what he wants. how they would value an ounce of metal, I don't know.
I think that if the dollar crashes Uncle sam will have a new currency waiting in the wings ready to ship out to the banks. Maybe it will be gold back or maybe it will be another version of fiat. In hyper inflation you could end up with a new $1 with Obama's face on it. They will allow you to trade your old bills in for the new ones but it may take $50,000 washingtons to get $1 Obama. Metal on the other hand is a commodity and has tangible value. Commodity vs. commodity value should be a bit more stable then fiat currency. rightnow you could buy around 30lbs of rice for one ounce of silver. I think that will be true in the new world as well not matter if it is obama cash or whatever.
If Metal is in a bubble I could be wrong. A house is a commodity and the housing bubble caused a lot of people to loss a lot of value in their housing investments. Other commodities could offer you the same security but non are as convienient, nonperishable, and easy to store. You could store a warehouse full of toilet paper if you want and it may hold it's value as well as metal as the dollar devalues but it takes up a lot more space, is a lot more fragile, and you will need a really big BOB if you plan to take your wealth with you when you leave.
To purchase gold/silver off the record you can go to coin shops, coin shows, pawn shops, craigs list, and sometimes those "we buy gold" places will give you a good deal if you buy with cash in hand rather then them have to send it in to the refinery. Always pay cash and your off the books. If you decide later to sell at a coin shop they will take down some of your info with the sale incase it turns out to be stolen. Precious metal forums always have buy/sell/trade sections.
