http://www.businessinsider.com/anthony-green-tutoring-2014-8
That promise seems to be enough for his well-heeled clientele (kids of Fortune 500 CEOs). And for this very small but wealthy minority, money is truly no object. Green charges $1,500 for 90 minutes of one-on-one tutoring, and he insists on a minimum of 14 90-minute sessions, with very rare exceptions.