The currency is nuggets of honey shaped gold. Shiny! To gain some, you'll need to join the Discord server, where gold nuggets can be found!
Pricing -
Common MYO: Free! Just ask MothZebra or another staff member.
Uncommon MYO: Free! just ask and add your mothling to the world if you make a mothling!
Rare MYO: 20,000 nuggets