I found a way to duplicate charms from the merchant!

[drowsy totem]

I purchased a durian charm and a heartforge from the merchant. I equipped the durian to my frenzied leader but it didn't have the desired effect.

I closed the game (switch) in case it hadn't saved and I could equip it to something else. When I booted the game back up I noticed the charm had been unequipped but I didn't have the heartforge. I still had the money for it, so I went back to the charm merchant.

She had another Durian...

You don't get the money back for the Durian, But as long as you have cash, you can purchase multiples of the same charm from the merchant

[light rain]

It's good that you have posted this issue, but you are not the first one to do it. Though I agree that this issue must be fixed.

Or maybe imploment that into the game? It could be cool if charm merchat would legally sell cooy chamrs, say you buy a charm and it's replaced by a new, same one with slightly increased price