Argentina and Greece both have barter systems, started by their citizens, as an answer to surviving their economic collapses.

What items do you have stockpiled that would benefit you in a barter society?

A few items I've collected include:

matches
lighters
candles
first aid supplies (Bandaids, Neosporin, rubbing alcohol, etc.)
OTC medicines
feminine products
toiletries (soap, shampoo, etc.)
laundry detergent
household cleaners

A few items on my wish list:

liquor (We don't drink, but I read about a Nat'l. Guardsman, after Katrina, traded an entire box of MRE's for a bottle of whiskey. He just went back and got a replacement box...no questions asked.)

cigarettes (We don't smoke, but this should be self explanatory.)

extra ammo in variety of calibers 

There's always gonna be the greedy psychopath that takes control of any food and water he can get his hands on so I would add silver and batteries 

Charmin extra soft mega rolls :) 

There's always gonna be the greedy psychopath that takes control of any food and water he can get his hands on so I would add silver and batteries

ammo 

I don't know that I would trade my ammo to anyone for anything honestly one round could get me more food shot the my barrel than I think I could get in a trade