Earlier quoted context omitted.
> The hammer did indeed cost $435. If the government wanted to buy another one, the contractor would have charged them an extra $435. But the above statement wasn't true.
The article has a nice example of this in the B2 bomber. The first 21 planes cost $2B each. The next one costs $700M. If, for some reason, we were to make a hundred or a thousand of them, the cost per plane would be even lower.
Think of it like you're buying a car, and you have the dealer add in a half-dozen options & extras, and then they bill you for all of them, as a package, as a single line item. If you then said the cost of each item in the package, including the car, was worth 1/7th the price you paid for the package, that would be the equivalent of what is going on here.