So how it is now, you can pay a few mills to make an instance.
But for myself i keep forgetting to bring cash, so how about you have an option.
you can either buy the instance or you can permanently unlock it.
When you want to perm unlock the instance you pay a higher fee, like you pay 1b to unlock the instance.
when its unlocked you can always create a free instance.
you can unlock those for all bosses, so its not that you pay 1b and you get all the instances.
no you need to pay 1b for each boss then.
thats my idea