Answer: About $1.6 trillion since 1973, or more than $5,700 per American, according to economist Thomas Stauffer. While I welcome the effort to spell out how much we pay for The Special Relationship, quite a bit of Stauffer's figure (delivered as part of a lecture commissioned by the US Army War College) seems speculative. He includes $420 billion in lost revenue from the '74 recession, and another $450 billion in increased oil prices from the oil embargo; these are the sort of hidden costs that can be variously attributed. (Where the Sauds really the sole drivers of the recession? And isn't the percentage of Mideast oil in our total consumption actually a pittance compared to Europe's, Japan's, or even Canada's, where gas prices are astronomically higher?) He also includes $50 billion to $60 billion in grants and bonds from US-based Jewish charities, which are "a net drain" on the United States economy; maybe, but it's not like those charitable donations would otherwise have been used to pay down the national debt.
Stauffer, who has been on this issue for some time, is described as "a frequent thorn in the side of the Israel lobby" in the article, but his various studies seem to focus mainly on oil economics. He's also a "true gentleman" who is quoted with some frequency by CS Monitor reporter David R. Francis.