What
@BigRed389 said. How does this help predict how much an acquisition program, which is usually made up of more than one new technologies with their own unknown cost, is going to cost?
In acquisitions, if you buy a lot of something after a Full Rate Production (FRP) decision your price/widget will go down. But you need to buy a lot of them and after FRP the configuration is usually fairly consistent. But prior to FRP you're doing EMD and LRIP buys of lower quantities of widgets that may not necessarily be the same thing that you buy at FRP.
To put it in terms of "normal human purchases," the DoD is NOT buying Camries and Accords. The DoD is asking a car manufacturer to make them a custom vehicle using technologies that have never been used before. So imagine what your cost would be if you decided an off the lot lambo isn't good enough for you. And the off the shelf mod kits that go with the ready made vehicle aren't good enough either. So instead you're going to ask Ferrari and Lamborghini to make your supercar vision a reality. And put some new lasers on it and make it be able to talk to your 1980s Beta VCR. So not only are you paying for the technology to make the materials, and the new space age material, and the lasers, and the backward compatibility with 1980s tech; you're also paying for all the smart (read expensive) engineers to make this dream a reality. Or, if cars aren't your thing, instead of building the house from the builders portfolio you've asked for a custom floorplan. Made out of carbon fibre and titanium. With some lasers on the top.