3 million?
With 200 000 euros, at 6% yearly interest rate (stock market), this gives a yearly interest of 12 000 euros. This is actually the same as my yearly expenses. So i could stop working right then.
With 400 000 euros, at 6% yearly interest rate, that is 24 000 euros per year. 2000 per month. Double of what i am spending now. So that would be very comfortable living. (+ another 10k yearly to spend from 70-110 years old so i spend everything)
With 500 000 i would have 100k to burn in addition.
btc x3 please in next 10 years 
Now, to buy useless status symbols, i am much too greedy for that. Hm. Perhaps it's not so useless for the women. But will buy plastic surgery instead. The calculations presented need to take inflation into account. Also, the stock market can not only fall short of your annualised returns, but destroy your wealth.
I do think $3 million is excessive for someone around 50 though. I'd have thought $1 mil was more than sufficient to retire.
Let's run a little bit with the hypothetical....
With an investment in traditional assets, they generally say that you are fairly safe to withdraw 4% per year and maintain your principle. With a $1million then that is an income of $40k per year, but maybe with bitcoin you could withdraw more? 10%, perhaps? 10% would put you at $100k per year while more or less maintaining the principle..