I agree with the others on getting a second opinion. Lort Smith in Melbourne usually have much lower costs than private vets.

I will also go against the majority and say that personally i could not justify paying a thousand dollars for surgery on one of my animals. I also would not want my parents to pay that much. I love them hugely, and would be devastated if i lost one of them but i could not spend that much on them. If they could live comfortably with the ailment i would do things to make it easier for them (non weightbearing exercise like swimming) but if they were in a lot of pain i would have to let them go.

Hope you find a solution.