In the side quest "A Daughter Ransomed" is there a way to save the girl, keep your money, and kill the bandits?
Yes walk up to them and use intimidate or persuasion. Tell them they have to send the girl to you first then you'll give them the money. Once they do that you just kill them/pay them.
Can someone editing the questions tags and mark it as Dragon Age: Origins - Awakening. As it's a quest in the expansion not the original.