Whilst $1m is a lot of money, As a 20-year old student right now, even with wise investment I don't I really don't see it lasting more than 10 years. It's not an amount that means I will never have to work again for the rest of my life and after I sort my whole family out (pretty big family) and get a crib of my own, half of it is gone.
$100m however will keep you, your whole family and enable your kids to make a decent life for themselves. I'd take that option all day even with the 50/50 chance of not getting it. If I'm unlucky and don't get cash out, f*ck it, I'll make it myself anyway.