However much it took.

I had a Dachshund growing up as a young child, and one day he had suffered a "slipped disk" while I was at school. I had came home, and my mother and I rushed him to the vet. There was surgery available for him (he would have to spend the rest of his life walking around with a "doggie wheelchair"), but my parents decided against it and chose to euthanize him. Even to this day, I have not forgiven them for that.

My dogs and other pets mean the world to me, especially Daisy, and if money was the only thing in the way, I would find SOME way to pay for it. But.. like Twisterdog said, if they were already suffering and there was almost no chance they would make it through surgery or whatever they needed, I would probably put them to sleep. Just whatever is best for them..