It also overlooks another pesky little problem: If the farmer is growing wheat...it's likely that ALL of his neighbors are doing...EXACTLY THE SAME THING. They'd choke on all that wheat they try to barter, because their neighbors are...uh...bartering wheat, too. The plumber and hardware store owner can only eat so much bread.
To shed all that barterable wheat, they'd need railroads. A functioning commodities exchange. A means of converting grain to a stable store of value (money).

I put out that idea of bartering as a means to survive... no, it’s not a perfect way.