Anti-Aircraft Missiles Aren't Cheap.

The principal anti-aircraft missile used by the U.S. Navy, the SM-2, costs $500,000 or so each.

While hardly any of these missiles have been used in wartime, each ship fires some of them periodically to make sure the system works.

In the aggregate, these tests cost the United States from $80-$150 million a year, although some of that cost is reimbursed by allies who buy the missiles from the U.S. Department of Defense for their own use.