Survivalist Preppers discussion

How will you barter or buy things and do you think we should save documents like are passport and birth certificate?
I think bartering (in the case currency becomes worthless) will be incredibly valuable and I am not talking about gold or silver because you can't eat or wear gold, but the best idea is to look at history, I believe that furs and pelts will be worth a lot in the event of a economic collapse, and according to history salt was incredibly valuable,but what is you ideas?

Water: Collection & purification
Food: seeds, non-perishable foods, spices
Cooking: Butane/propane, rocket stoves, camp stoves, lighters, matches
Heat/Shelter: Clothing, blankets, heaters, woodstoves
Medical: First aid & sanitation items
Self-Defense/Hunting: Knives, guns & ammo, bows & arrows, fishing gear
Tools....

I wouldn't want to barter with ammunition or guns because then they could shoot you and take everything

It would depend on your location. In warmer climates, sunscreen hats and insect repellant would be valuable. Soap, toilet paper, superglue, hand tools, and a basic sewing kit would be valuable everywhere.