Whilibird is correct in that people should get the basics covered before venturing out into PMs.
I remember reading a story regarding a special forces soldier separated from his group and becoming lost in Iraq. No food. No water remaining. He trudged for miles across the arid landscape in the attempt to re-connect with friendly forces. What he did have, (and I hear all SF soldiers carry it) was a 1 oz. gold eagle. He finally stumbled into a village close to death from dehydration. He hadn’t eaten in several day, either. With no money, he was able to trade that gold coin for some food and water, which saved his life. People might say that the gold wasn’t worth much. I think that trooper would disagree.