According to Warren Buffett, the formula for valuing an asset purchased for gain is the same now as it was when articulated by Aesop long ago.From the 2000 Berkshire Hathaway (BRKa) shareholder letter:"...Aesop and his enduring, though somewhat incomplete, investment insight was 'a bird in the hand is worth two in the bush.' To flesh out this principle, you must answer only three questions. How certain are you that there are indeed birds in the bush? When will they emerge and how many will there be? What is the risk-free interest rate (which...