To imitate the bartering (trading) sessions in the American Colonies, I invented this interdisciplinary activity where students bring in their own items to trade (barter) with each other with no money exchanges. I also invented several alternative games to vary the activity. It can be done in one class session. Besides learning about bartering and the techniques of trading, they learn that good and bad deals can be made and that it is a learning process to develop the skills of negotiating and trading.
That's horse trading! They love "trading" but they also learn the value of "hot" properties and junky items.