Board Thread:Troubleshooting/@comment-99.250.104.141-20160608020417/@comment-30514476-20170112001245

I believe that coins used to be needed alongside a key to open rooms and I think it was rubies to open locked by level rooms. But yeah, coins are only used at the  3 merchants (Fortune Teller, Blacksmith, and Inventor) to craft. There's nothing else coins are useful for.