As an outsider, who writes software for a living (proper, highly available transactional systems [finance industry but I do know some general stuff]). This amount of money is simply staggering. Even if we assume the published number (4.3B), 3% inflation, a relatively aggressive annualised ROI and 10 years over which to apply the costs, that turns into between 80 and 160 [20% ROI to 10% _annual_ ROI] million dollars per year in costs. IN COSTS. Even if you margin those costs at 33% (profit is already accounted for so the margin is on costs and risk) that's still 50 - 100 million dollars a year of costs to develop and support this system every year for 10 years. WTF kind of project are they planning? People have written software that changed the freaking world with a fraction of that amount of money.
Now having said all that, I have a little window on the way a different government developed their budget for an IT project. They knew that the new project would make 60 people redundant so they looked at the cost of those people, multiplied it by some number of years for the scope of the new system and went... There you go 30 million dollars.
There is something very, very, very wrong with government.
BTW, There are about 20M veterans in the USA, give em all 200 bucks and let them keep scans of their own records on a freaking thumb drive. Backed up to, S3 or something. That might even actually work!