I've seen several of these posts on different forums. It's always something to ponder. Stocking some items is difficult due to expiration dates, etc. Think of simple items that are easy to get now, have indefinite storage if stored properly, don’t take up too much space and will be easy to barter with later. For me:
Salt
Sugar
Honey
Coffee
Nails
Candles
Matches
Canning jars/lids
Those are some of my main items I pick up extra when I go to the store. I often have a good stock of batteries which have a decent shelf life and they get rotated...not enough to use for normal barter, but good for emergencies.
Having a trade or even a hobby that can turn into one is probably your best bet.
Blacksmithing
Gardening/Canning
Meat processing and possibly curing/smoking
Cutting firewood
Gunsmithing
Carpentry
Plumbing
Electrical Work
Wood Working
Metal Working
Beer Making
Reloading
Bicycle repair (may be a big asset once gas is too expensive to get)
Raising Livestock (chickens, goats, pigs, rabbits)
Volunteer EMS
Amateur Radio (important for news outside the area/communication)
Livestock and gardening can be replenishable trade goods. You will never be able to stock everything for yourself for long term, so you'll need something that you can trade and barter with in the long term. I don't plan to use ammo for trading, but if it was a medical emergency, you bet. I have plenty of knives, guns, flashlights, tactical gear and other toys that could be used, but it would be very select and last-resort bartering.
We have a garden to get set up and plan to raise chickens and possibly rabbits. Now that we have a nice stocked lake, water and fish are tremendous assets...especially since water was a big concern in TX where we lived previously. I also have my beaver population for fur and meat

We also have a farm up the road that has cows (trading for milk), horses (manure for the garden), and there's a fish hatchery down the road a ways...
Average income is quite low where we now live. A lot of locals make their living off of selling simple goods and trade work. Bartering stored consumables is a short term plan; having a trade or replenishable goods (eggs, canning garden harvests) is a long term strategy. Knowing the local neighbors can be a big asset when it comes to just lending a hand with manual labor. If a tree damages a neighbor’s house, helping fix it and seal it up; helping mend a fence, etc. You’ll have to get involved in your local community, neighborhood as you’ll need to eventually find a doctor, dentist or other critical service that may be beyond your own skill sets.
ROCK6