I bet the bloke who owns the hamburger store will get a little suspicious when old mate sets up a shop just down the road :lol:
It would be easier to use a crypto-currency? Barter systems are too inefficient. Any significant barter system will be investigated or shut-down by the do-gooders in government. Because they've got all the guns.
You will have crypto currency, barter systems can not be shut down if it is between individuals, it is like cash in hand. You can not stop two individuals talking and coming to a non cash agreement. No matter what system you put in place people will come up with something to get around it.