1. Obviously on the quality of life. I once opted to have my cat put to sleep rather than have her go through exploratory surgery when she was very sick. I didn't think she had much of a chance of pulling through and I didn't want her to suffer. (and I cried for a week afterwards)

2. On my current financial situation. Right now both my husband and I are employed (which is a very nifty thing to be here in Oregon), and would be able to absorb the expense.

3. I dearly love and adore my cats, but my parents are getting on in years, and I would take care of them first before my cats.

So, like I said at the beginning, it depends. You sometimes don't know until it happens.