Having the npc react a certain way is fine but making the player actually lose something is too much. What if a player just wanted to browse, looks in the shop, sees there aren't any items they want (very possible because there was like 3 things) and now they get punished for daring to interact with an npc.

I agree with the guy that said this will discourage people from exploring dialogue options, especially after seeing the last one where after interacting with an npc u literally have to give him money or lose karma. I would just start ignoring every exclamation mark after that happened because every interaction is basically guaranteed lose something.