Basic Unit of Trade - the Blanket: The basic unit of trade between native people was the blanket. The value of everything was expressed in blankets. Trades between clans were arranged in advance. Once they were arranged, they were conducted like live performance plays. Everyone knew their role.
First, a lavish display of blankets would be brought to the trading place. A ridiculously low offer would be made, much lower than that agreed on in advance. The seller would accept it, to show how little he cared about money.
Then all the seller's friends would quickly say, "No, you can't accept that. It's too low. Tell them to go home."
Then the buyers would add a blanket or two. This continued until they reached the agreed upon price. Everyone had a great time.
Coppers: With the coming of new wealth from the fur trade, these early native people were able to add a new form of money, the copper. A copper was a large shield-like piece of copper, painted in bright colors. In 1893, a copper was worth 5000 blankets. This copper's nickname was "Making the House Empty of Blankets."
Soon, they added a bigger and better copper worth 6000 blankets - The Steelhead Salmon Copper ("It glides out of ones hands like a salmon.") Soon, they introduced a third copper worth 7000 blankets called "All Other Coppers Are Ashamed to Look at It."
If someone offered you a 7000 blanket copper, and you said no, you would lose face. That would imply you could not afford to buy it. If you said yes, your entire clan would have to come up with the equivalent of 7000 blankets. If you could not come up with 7000 blankets, you would have to sell some of your clan into slavery to pay the debt. If you could not afford it, you had to lose face and slide down the social scale or become a slave.