Board Thread:Suggestions forum/@comment-26553378-20161202225207/@comment-26119768-20161203010041

Alternatively, you could now craft coins out of bronze or iron nuggets, and when used, bronze coins have a 60% chance of being rejected and calling down the wrath of the merchant, and iron coins have a 45% chance of being rejected.

Having coins rejected would bring an alignment penalty with the merchant's faction, and maybe call a few guards to deal with the riffraff (you).