There may someday come a time when our current form of currency won’t be worth the paper it is printed on. If this were to come to pass, you may find yourself in need of either goods or services and need to render some form of payment. Thus, it may be prudent to stock up on a few things that are somewhat inexpensive now but may be worth their weight in gold down the road.
The first thing that comes to mind are those items we might consider vices now. Tobacco and booze top that list. There is little need to go out and get top shelf product either. Those people who would be willing to trade you some extra meat for booze won’t be concerned too much if it isn’t Glenfiddich single malt. For tobacco, I’d suggest storing it in your freezer (while it is still working), as well as some rolling papers. Just buy the larger canisters of loose tobacco as that’s much cheaper than a carton or two of even the cheapest cigarettes.
Coffee is another great idea, though I’d suggest storing it as “raw” beans, roast and grind them as needed. Candy, gum, and other sweets, if stored properly, will last a good, long time.
Moving away from consumables, some hard goods to keep on hand for barter would include needles, thread, matches, candles, blankets, soap, and fishing supplies (hooks, line, etc.).
I have seen some people advocate using ammunition, especially .22 shells, as currency. Personally, I don’t like the idea of giving bullets to anyone who might conceivably use them against me at some point.
How many fish hooks would equal a can of food? I have no idea, that’d be up to the people conducting the trade. Remember though, the best trade is one where each person thinks they got the better deal.
Aside from stocking up on goods, you might also consider what skills you have that might be “marketable” down the road. If you know how to sew by hand, you could probably trade some mending for extra candles or something. Be sure to stock up on anything and everything you might need for your hobby/career.
Remember, the items you stock up on for barter purposes are secondary to the stuff you put aside for you and your family. Meaning, only worry about the barter items after you’ve stocked up on what you and yours need to survive.