Many people purchase gold financial instruments, a peice of paper that claims gold ownership. At the end of the day there is not enough mined gold in the world to deliver to everyone who has a claim on gold. The demand clearly outweighs the supply. Only the issuers win in this scenario as it is impossible to fulfill such an idealistic demand. In addition, no one is going to walk around with a bar of gold for exchange. It is only a hedging instrument. One can go bearish and purchase a put against an index and limit their downside risk.
In an economic collaspe it is more reasonable to purchase cases of liquor, soap, guns, bullets, clothes, garbage bags etc...tradeable consumerable items. gold is too hard to trade in a collaspe unless you hang around the rich. Buffet doesn't purchase common stock like normal folk he purchases perferred shares or warrants in many cases. Again he limits his downside risk, in case of bankruptcy those positions get paid first.