I differ a lot in opinion on this topic from some of you. Not because I am cruel, or want to spend excessively elsewhere or anything like that. (for the record we do live simply, simple cars, simple stuff, frugal where we can).
We are on a small farm. Life and death are a constant. We butcher chickens & goats. Milk Goats. We also raise rabbits for fur that our daughter spins. Needless to say, life and death is a reality. It's fun to watch baby chicks hatch from eggs, and somewhat sad to see them on butchering day, but always thankful at the table.
Dogs are the same way. See puppies born, treat them well, but they eventually grow old, or get sick, and will die. It's just a reality that is a constant around here. In fact, one of our rabbits caught a disease (we think a rat bit her) and I took it out back and shot it. Sad, but reality. To spend money at a vets office is very foreign to me, especially that kind of money.
I mean if it was something simple, cheap, OK. But once we start crossing several hundred dollars, they either live with it or get put down. It's just the nature of things. Love animals, love dogs. We'll treat them right, feed them good, give them loads of attention, but we aren't going to spend that kind of money on an animal.