Stock up on items you can barter

Agreed! If you have no manufacturing skills you're fucked. Everyone is a fucking 'shopkeeper' but there won't be much getting produced, so your barter items won't last too long.
I am a metal worker with many primitive tools...just give the steel and I'll make it :-)

I've purchased from Sweet Marias before, but these guys are generally less expensive.

[link to www.ccmcoffee.com]

Sweet Marias has online info on how to roast the beans.

Salt is probably the cheapest and easiest thing to use as barter post-collapse. If you were to purchase a lot of table salt, it won't go bad, and you'll just eventually use it if there isn't a collapse.

Salt is very difficult to harvest unless you're near an ocean. There are of course salt mines, but they won't be mining for it again until they wise up and figure out that what they have is more valuable than gold post-collapse.

The best way to harvest salt from the ocean is to evaporate it slowly, not by heating. Heating it will waste too much wood.
The method can be found on this page:
Thread: Last minute tips for parents when the SHTF (Page 16)

Salt will be your main preservative, that and vinegar. You'll run out of canning lids, so you might think about purchasing reusable ones instead now.

If you look in google books, and you check with your state historical society, they can tell you were salt was harvested in the past. Usually it was mined, but also found in natural salt licks like:
[link to parks.ky.gov]
[link to mostateparks.com]

These may have played out, but they also might be potential salt mining operations in the future.

Native American tribes set up trade networks across huge areas of North American Central America and down into South America. If they could do it, then we could do it again too.

Iodine is a necessary nutrient and difficult to acquire. It's why iodine is added to salt now, otherwise we'd have lots of people with goiters as they used to have before this method was utilized. It's another selling point for iodized salt purchased now for the purpose of trading post-collapse.

A source of iodine is black walnut. This is another way that black walnut can be used as a trade item. It is extracted from the blackened hulls on the outside of walnuts, and it also produces ink and dark brown dye. It also produces a valuable medicine. See:
Thread: Last minute tips for parents when the SHTF (Page 18)