These are alternate currency in game. They can be used to buy in game items from coto merchant, repair item max durability and pay taxes(1:3500g) You can sell them to some players vendor and convert them to gold. Current rate about 1600g to 1 coto.
This always gets me, because no one is selling these for anywhere near 3,500g on the markets. So in essence, who would pay 3,500g (or equivalent) in taxes with in-game gold, when you can buy a COTO for ~1,500g? Or am I seriously missing something (likely).
Coto and gold has dollar value, this give their in game coto to gold relationship. Coto is about 100 for $85 ignoring Black Friday bonus. Gold is about 100,000 to $35-$40. If you reference them both, coto should be about 2150-2450. This relationship play a more important role to determine in game coto prices then the tax rate conversion. Looking at it, coto should and probably go up higher.
Something to keep in mind is that the gsme is flooded with cotos atm from pledgers. this will decrease with time and see prices stabalize. im sure people willstill spend money to undercut in game gold but you alrrady see it. was 900 - 1.2k a coto for a while. seems around 1.5 to 1.7 now.