The motetization model for the developers is revenue share. The revenue is shared with developers after some costs and the prize pool share is extracted.
If a game is monetized by IAPs, developer earnings depend on how much Fundy is spent on their game/s. The greater the amount of Fundy spent on your game, the greater the amount of winnings is.
The amount of Fundy spent is gathered up monthly and the dollar conversion is calculated according to the Fundy package sales took place in that month. There will be differences from month to month due to the change of package sales. So the unit price is calculated every month separately and the revenue share is done accordingly.