1million
10 million
100 million
you'll still be miserable, if you don't find meaning in your life.
the difference is being miserable on a wooden chair or a goldendiamond chair.
but still it's more important to think about this question:
what are you doing with your life?
No offense but this is a little off-topic, having the what you said amount will make your life a happy life, "miserable" is not the right term to use in this statement. Miserable life is a life where you have so many problems, the number one of that is financial problem, and having a huge amount of money will solve that problem. I think what you were trying to say is that you're just going to nonsense a life, because you can't spend that money alone,
And if you die, your money would go to someone who will stole it on your bank, or probably your lawyer would donate it to some charities or hospitals that needed it.
For most of the people the meaning and aim of their lives is to earn money, no matter how it comes. If it comes from unfair means, it will make the life miserable in the long run.
If someone wins big from gambling, he will not stop trying it again because its human nature that they will try the same thing again and again, if it gives them profits.