I'm glad Rubino spoke of Black markets as I have typed about on a related thread. I wonder if a profession of arbiter would come into existence-(a person who decides what the value of one commodity is to another). In other words, Is my 100 oz. of silver tradeable for a horse, or a six month food supply for a 1000rds of 223. An Arbiter would take a small fee that both parties would have to agree to beforehand and then decide if the deal was fair.
And that being said, the Arbiter would have to have a very fluid knowledge of current events and constant price changes-kind of like a commodities trader. Just a thought.