I think the best bartering item would be medicines such as antibiotics. If the SHTF there will be a lot of junk all over the place what is needed is to be able to put the junk back together or make something out of it.
I tend to agree people can use it to protect themselves and take small game, and it would be much less likely to be coming back at you if you are well armed.22 long rifle ammo by the brick.
I just had a mental image of the check out folks where you buy your TP and what conversations they have as you haul out your 200th role for the week....This is as easy as toilet paper. Here is why.
1). It is most affordable. Shop around and find the smallest roll, cheapest kind, and spend as little as possible because when it becomes a barter item that expensive charming might be nice but the cheap stuff will still be in high demand.
2). Because anyone with an attic can store it there and let it serve as insulation. How many "preps" save you money while in storage and don't degrade any or hardly any.
My current deal is a 24 roll dual ply from a local grocery chain for $3.98 plus tax. It costs me less than 18 cents a roll. It's a large flat package that fits nicely in the attic and for under 10 bucks I get 48 barter items that in Venezuela would already be worth plenty.