I feel the .22 is the ultimate must have weapon. So, the ammo could be a currency in bad times. I like to keep 10-20,000 on hand at all times.
That sounds like a lot but a bunch of kids at a range with a half dozen .22's will burn up a couple of thousand rounds in an hour or two without much trouble.
One ounce gets about 1,000 now. 500 of the more expensive stuff. In a real pinch an ounce per box of 50 might seem bargain territory.
We'd be in a new old world. Hard currency and supply and demand. How primitive! LOL!