Ammo, fuel, food ( in storage form ), gold and salt will be commerce. Salt will be in demand as much as ammo.
You do not want to live near a bunch of people if you can help it. The 'have-nots' will seek out those that 'have' and take. The pain of being without will drive most people to commit crimes they normally would not commit.
AND, if you think about 'helping them out', you had better have more than enough for the rest of your life as word will spread and everyone will be at your doorstep.
Cruel as this sounds, it is true.
