Though if you look at most tech haevy programs cost over-runs were collosal during the 90s. The tech developed too rapidly that new stuff would be junk before the requisition could be closed.
But in point of fact you don't classify less than the current state-of-the-art with nontheless very real defense capability and security value as "junk". Witness we still use ships that are over 40 years old, and planes over 30 years old, updated to be sure, but they represent a huge investment, not to be cavalierly dismissed as "junk".
Ditto missile defense deployments. The Brilliant Pebbles program, as the Independent Working Group concluded...would have bought us at least 20 years of robustly effective missile defense for only $11 billion.
Today, we have no real defenses worthy of the name deployed, and are down still another $50 billion in paper studies. Amazing isn't it how paper can suddenly cost so much, and give you so little?
And meanwhile, this Administration killed a number of the cures for the sabotage against missile defense that Clinton had ordered [going with a puny ground based interceptor, laming up the speed and range of the SM-3 Aegis interceptor, killing outright Theater Ballistic Missile Defense etc.] ...all under a cloak of silence. The dogs did not bark. The MSM and Rats remain silent in approval of anything which undercuts real defense...and the conservatives remained silent falsely hoping that the Administration was simply going on to something better. We now know different.