Replacing USD with "Tokens"

Hi everyone,

I am working on a concept that requires the site to use a digital currency. For the time being I am calling them “tokens.” The concept is an auction website that uses these tokens as the currency instead of USD or any other form of currency. I am trying to find a plugin that allows users to gain and lose tokens based on their sales and purchases.

Users would gain ‘x’ amount of tokens after their item sells at auction. The buyer would lose the same amount of tokens after their purchase. Other parameters would include, but not limited to, signing up – gain 1000 tokens. Refer a friend – gain 500 tokens.

Each user would sign up for the service. An would have their own personal “wallet” that maintains their accumulation of tokens.

Also in the event a buyer does not have enough tokens from selling their own items. I would like to include a marketplace for tokens that users can purchase for USD. example $1.00 = 1000 tokens. Much like a mobile game. Run out of lives. Purchase more, if they user so desires.

If anyone could please point me in the right direction it would be much appreciated. I have tried searches for such a plugin, but have come up short. Most searches refer me to BitCoin or some other cryptocurrency. If anyone has a way to help me narrow down my search for what I am looking for I would greatly appreciate it. Thank you.