That's a myth. Bartering wasn't really a thing as it's presented in most lower level history classes.

Most civilizations dealt in community sharing before currency was invented.

It wasn't a case of "I have 3 chickens for your 12 loafs of bread." It was more like "I grew more wheat than I need this season and my neighbors goats are producing more milk than they need. If we put it together, we both have a nice meal."