I don't need much to live, and I haven't really thought of how much things cost. Let's just say if I gave myself 3000$ a month. that's 36k a year which would be 1.62 million from now until I'm 65. plush I'd have an extra million or 2 to spend on anything I actually wanted.
about 1 to 2 million would be for the things I need like, food, and clothes, and such. another million to buy whatever I wanted, and The rest will go to various charities and research.