It might be useful to look at what people found to be worth trading in other near apocalypses.
A lot of the precious items in collapsed economies are things thought of as either trash or as luxuries in healthy economies.
Post WWII Germany saw a high demand for rubber scraps and belt leather, as well as for booze and nylon stockings.
If you look at some of the collapsed and failed economies in Africa and the East you will see other clues.
In Dem. Rep. Congo the offering was bicycles, roofing tin, and sewing machines in exchange for weapons.
This was in a country torn up with civil war.
http://news.bbc.co.uk/2/hi/africa/5180144.stmWhether you are pro or anti-gun this should be looked at as an indicator of what is of more value.
Often the most important trade items are skills. Again there are many examples in recent events.
IMHO, Jeff and Art have it down pretty good.
Previous Topic
Index
