A barter economy is very temporary and short-lived. Gold has been money for 3000 years.
I liked gold until I tried to use a 1 ounce coin for a firearm at a gunshow in Arizona, just as a test.
No one, and I mean, no one was interested in it.
It might be good after the currency goes nuts. But I have serious doubts about its use as money in an emergency.
People have simply got out of the habit of using it.
Brokers would certainly come into use, if they were not outlawed, but it would take a while, and that while could be critical.