In this business, simply "doing the math" would stop us right in our tracks. Luckily, we have algebra on our side. A daunting equation can always be rescued by that helpfully vague variable, 'x', the unquantifiable ardor of wealthy people: their competitive instinct, their sportsmanship, or simply their outsized egos. At the top of the market, after all, the dollars they spend are not the same as the dollars used by the rest of us to buy coffee or gas. It's not like "real" money at all. But that doesn't...