Imagine you're a bandit, possibly squatting in the very cottage you live in, when a rando hero looking mofo is just wandering up to the cottage to investigate. He spots you, with half an animal corpse and a weapon, most likely having already added up that you don't own this place.
After the fight, she lays it out quite plain. She can't have you running to the guards. She takes no joy or pleasure in killing, her reaction says as much too. She doesn't want your money, she wants her own safety.
Urka is the same, if you're a coward and refuse her twice after losing 2 fights she'll kill you too. She takes no joy in it either. For her though, it's about honour and dignity, which you show none of by running from her twice.
All ya gotta do is empty their nut.