Recall that the estimate by Yale University econ prof William Nordhaus et. al. estimated in 2002 that the war would cost $1 billion. He may have been off by 150%!
New Statesman - Iraq: the hidden cost of the war: "Let me pause to explain those deceptive figures. Look at the latest official toll of US fatalities and wounded in the media, and you will see something like 3,160 dead and 23,785 wounded (that 'includes 13,250 personnel who returned to duty within 72 hours', the Washington Post told us helpfully on 4 March). From this, you might assume that only 11,000 or so troops, in effect, have been wounded in Iraq. But Bilmes discovered that the Bush administration was keeping two separate sets of statistics of those wounded: one (like the above) issued by the Pentagon and therefore used by the media, and the other by the Department of Veterans Affairs - a government department autonomous from the Pentagon. At the beginning of this year, the Pentagon was putting out a figure of roughly 23,000 wounded, but the VA was quietly saying that more than 50,000 had, in fact, been wounded."