Let's set up an exchange where people can post bids and asks, for example:
- You post an order to buy 5000 coral at 0.022BTC (2 USD)
- I post an order to sell 3000 coral at 0.011BTC (1 USD)
The exchange fills what it could: I give transfer coral to you and you give me bitcoins. I'm too lazy to do the fucking math for the example, you can figure it out if you want to.
I'm not sure who the spread should go to, though. Maybe it could go into a special fund to buy sex toys for the mods.