"You were amazing back there," Melting Snow exclaimed once they were outside the shop. He couldn't believe that Xinya got an extra 100 gold coins from that exchange. "But you shouldn't have risked it."
Melting Snow saw all sorts of warnings on the forums about how players shouldn't try to barter with the NPCs. It was said to be one of the hardest things to do, with only a 5% chance of being successful, and if a player fails then they better move to another town.
He wondered if that's the reason why Drifting Cloud took the chance since he knew that they would be leaving this village soon. Either way, even if what he did was amazing it was still very reckless.
If the NPC had gotten upset and kicked them out of his shop, then they wouldn't have been able to sell the mirror. Which would have been terrible, since they would have needed to find another town quickly.