We have a game running where everyone has his own currency. Some collaborate and some don't. Everyone who starts a store should buy something very basic. A carpenter should buy logs, a mason should accept stone. You can also accept food, so the others can afford your items. But the whole thing only works on at least a medium difficulty where you can't do every job on your own. It works - but not on every serversetting If you wish to work closer together with a smaller group you can add a 2nd whitelisted shop where only some people can buy your goods for less or nothing.