uhhh...think the falling dollar has someting to do with the prices here? Demand didn't need to quadruple...it only needed to edge up enough to throw the supply-demand balance out of whack. China and India have accomplished this quite handily, and then some. China also continues to underwrite the price of fuel in their country, as does much of the middle east, further dampening the supply and demand from striking a balance at a lower price point.
1999 e46 328i Ti Silver / Black[retired]
2007 e90 335xi Jet Black / Black[retired]
2011 e70 X5 35d Vermillion Red / Cinnamon
2011 e92 M3 LeMans / Fox Red extended