HOWEVER, this pet belongs to someone who has done WAY more for him that most people would (and I could be wrong, but I think if there were a better/surer prognosis, would do it again here).
You are not wrong. One part of me would pay the money for the surgery, knowing it was a risk. Knowing he may not even make it. Not knowing what the next thing might be. And in a way we have already done that. This is the next thing.

But the logical part of me says "how much more, when do you stop? We have certain obligations that cannot be changed. Things that we have committed to that are not an optional, repair work on the house, our son's wedding...."

Then the emotional side of me says you have just spent money on other things but you draw the line here!" But believe me, we have spent more than most people spend on a typical pet. He has had more than his share of issues and it feels somewhat like living waiting for the other shoe to drop with him.

Back and forth. I guess this is normal.

It's so hard to finally draw the line and not feel remorse along with all of the sadness.