I have a lot of experience with federal government acquisition contracts, both on the government side when I was a budget officer and later a special agent investigating contractor fraud, and also working for defense contractors on contracts of all sizes. It doesn't do much good to compare the cost of a specialized vehicle like the ISV to a vehicle you can buy at the Chevy dealer. When the government gets involved, the requirements stipulated in the contract are not limited to the performance of the finished product. There are very specific requirements on cost and schedule reporting (Earned Value Management, etc), all manner of engineering reviews, extensive testing, etc. It's a rare contract that does not involve the government changing its mind on requirements, and each change has a big effect on cost. The government program office pays for all of this in the contract.