For you my friend, special price, 10 million.
Seriously though, this question has no answer. How big are your returns, what are your expenditures, how consistent are your returns, it's all variable.
Best way to go about it is to live massively below your means. That means you'd spend only 10-20% of your trading returns on living expenses.
Hey that's the min. account size for the platinum club at optionsellers.com where they short futures options!