Less people = more wild game. Ammo isn't a worry when hunting or trapping. You can use snares for smaller critters and bows to hunt animals as large as a deer. People don't understand that MREs, SPAM and canned food are emergency food. They are everday eating food when nothing else is available. Any prepper knows they need to grow their own food even if you have to do it in a green house or an indoor grow. Those hanging tomato planters were developed by a prepper no doubt.
Pioneers in the progression west in the USA did just what I'm talking about. They had to worry about unfriendlies, nature and disease. Some of them died and some of them lived. The better prepared lived and prospered.
It has been said time after time in this forum that the likelihood of a Zpoc isn't very high. Natural disasters and economic breakdown is much higher. In an economic breakdown cash will likely be worthless. People will rely on trade and barter. Someone with gold, silver, other shiny metals or jewels will be considered wealthy but will have to be able to hold on to what they have.
I think the people who will be the wealthy in an apocalyptic disaster will be those who can manufacture. There will be machine shops everywhere just waiting to start up. There are raw materials all over the place. The people who get that stuff up and rolling in safety will be "Boss". BARTERTOWN BABY!