Introducing a new local currency after an event

[grumpy old man]

that may be true for a small group of people, but not if you sell the idea to other people this is where you need a manager so they can keep things fair and deal with anyone, they could sell the idea to other people which would lead to the market place expanding making more choice for people.
by doing this capitalism is born!.
if some set the price of their things too high and people can't pay that price you get robbed and lose your stuff or the people find another way to get it from some where?