Barter items are very important!Oh yeah, Money.
Might need to bribe folks along the way to your Bug-out location.
Water bottles, mini liquor bottles, cigs, chew tobacco, diapers, toiletries, lighters etc
Money might be useless in certain situations, but I'd imagine silver and gold might be worth something.
Water will be the most valuable commodity for sure.
Water filters and purifier tabs are key!