That’s a hand full of “Destroy one local economy”. If people are mostly using copper and silver at 100 copper to a silver and 100 silver to a gold- a single gold piece would be used to purchase large quantities of items or for payment on things like entire buildings. Also Kaylin’s joke, she can’t help it, she just learned that that 200 years of difference is actually 300- but that doesn’t line up with the disappearance of adventurers… If they vanished 200 years ago, and she vanished 300 years ago- what the heck is going on?