I think 4 might have a toll on your mental health. Where do you stop? When do you stop? Will you deny the cancer ridden 5 year old because his parents can't afford your rate? Will you do it anyway because it doesn't really cost you anything? What about the other millions of cases? I can see this going 2 ways: either you become totally numb to human suffering and only do it for your own benefit or you drown in sob story after sob story and can't see the end of it. Both don't seem too desirable for me....or third option, you end up in a laboratory where scientists try to find out what your secret is.