So I suppose that would be under the services classification instead of goods.

I have to admit that I am a bit confused by the idea of hoarding up stockpiles of stuff to use for barter.

For one thing it assumes that everything has collapsed to the point that markets are closed and are going to stay closed for a long time. Yet at the same times it assumes that things will be stable enough to allow people to have a place stable enough to stache their cache and trade from.

I would think anything severe enough to force you into a barter economy might easily turn you into a refugee, and in that case skills are usually easier to transport than stores are, and have a much higher trading value per pound.

Another thing I wonder is if all the barter-trade-stockpilers are going to end up with all the same stuff.
You might find the PAW to be overstocked with tobacco, booze and guns but very short on laundry soap.