Pet owners/lovers, what's your personal $$$ cap?

Even when we love them and commit to their care and welfare, what do you consider to be the maximum you are willing/able to spend on their medical care?
What’s the tipping point for you? Assuming you are comfortable but not wealthy, where is the line that most of us might have to draw at some point?

This is a personal conundrum for me right now, I would like to know how others think.

Thanks.