Funkedup, you need to add to the cost the cost of increased security measures due to increased terrorist threat. And the loss of life and property in the event of an attack.
An attack is extremely likely - Saddam has standng orders for it to happen if the US strikes. And there are lots of freelancing terrorists that'll get new recruits in the events of a war.
The cost also has other more qualitative sides. As witnessed in Afghanistan, it is hard to create a democracy. Iraq is as divided as the Balkans is culturally and there'll be an struggle for democracy to be put int place. This will cost too.
If the resentment grows enough in various populations, some Middle Eastern government might be overthrown. Oil prices go up.
A few bombs on planes or at tourist resorts will hit those sectors very hard. Add that as well.
Of course all that can happen without a war, but a war makes them much more likely to occur.
Many hidden costs, aside from the obvious expenditure on fuel, bombs, surveillance, logistics and the like.
Unlike some here, I care a great deal about the Iraqi people. I've met refugees here - they're quite well educated, extremely kind and very resilient. I seem them sort of like the Polacks during the Soviet occupation.
By far they're nicer than Somalis, Palestinians etc as a cultural group - and more western. Was invited to the home of an ex chopper pilot from Iraq who fought in the Iran-Iraq war and briefly in the Gulf (that is, he flew his chopper for a few miles, landed, exited, waited a few hours and saw it get blown up by an unseen bomber). Very friendly environment and they do everything for their guests - quite unlike Danes or westerners in general. The chap offered me his bed, opting to sleep on the floor. I declined of course, but the offer was genuine. I do think that Arab culture in this regard is superior to western one - if they had $10 left, they'd give you 7 and keep 3 if you were in need. At least the educated types I've met. I do not dismiss their hospitality - yes, I disagree with their views on women etc, but I also recognize good aspects of their culture, and bad about my own.
I think they deserve to claim their nation back. $700 I'd pay. Add a 0 and I'd pay that too.
Once you meet the people, your views change. If you sit and hang around your ethnic group with the same view all the time, it is much easier not to give a damn about other cultural and ethnic groups. Me, I cannot be that...low.