How much would it cost for a kitten leg amputation?

I found a kitten on my parents' property today. She can't be much more than 10 weeks old. She appears to have badly broken her right rear leg and it has healed in such a way that she can't use it at all. It doesn't appear to be causing pain, but I have a feeling the vet will recommend amputation. I didn't want to bring her to a shelter, because I'm sure she'd be euthanized, but I want to be prepared for how much an amputation would cost. I REALLY want to save this cat's life....