We have a cat with FIV. We didn't know he had FIV when we got him and by the time we found out he was already family. For the most part he is healthy and active, but at times when he gets sick he gets very sick. Recently, he had to stay in the veterinary hospital for about a week, in total the treatments and stay cost over $2,000. He has since recovered and is back to his healthy state. He's a character and we love him dearly. It hurts to spend that much money, but fortunately we make enough income to be able to get by. I don't have an answer to your question, as I know there is a limit to how much I would spend... fortunately we haven't come to that point yet. But I don't mind spending money to guard my heart even if it means I can't get a new car or a big screen TV.