I was thinking in fives recently.
$5,000 would get me through September plus maybe pay for a root canal.
$50,000 would get me through the next year plus maybe pay for a trip overseas (maybe South America).
$500,000 would pay for ten or more years of life, depending on what I did with it. I could give friends and relatives small monthly stipends to help them out. I could give larger (or more) donations to charity.
$5,000,000 would be enough for the rest of my life. I could give friends loans or gifts; I could buy a car for me, my friend, my brother and sister-in-law. I could buy a house or two. I could travel around the states and around the world. In my mind, I would set up auto-payments for all my bills and leave the country as soon as possible. I don't know if that's realistic but it's what I tell myself I would do.
$50,000,000 would be enough to do things I've only dreamed of: Start a small foundation. Finance short film projects. Make commercials and pay for them to be aired. Buy a full-page ad in the NYTimes (or USA Today). Buy billboard space and put up message billboards all over. Travel everywhere. Start innovative programs. Pay for everything myself.