One more expense I forgot to address is private contractors who significantly overcharge the govt.
This is federal, but the same thing happens at a local level:
The Defense Department overpaid a billionaire oilman by as much as $200 million on several military contracts valued at nearly $2.7 billion, an internal audit has found.
Rep. Henry Waxman, D-Calif. led a probe against Sargeant in October 2008, accusing him of using his close relationship with Jordan’s royal family to secure exclusive rights over supply routes to U.S. bases in western Iraq, according to the Washington Post.
The Pentagon would have saved at least $180 million by choosing the lowest bidders on fuel contracts awarded to Sargeant, Waxman had calculated. The audit found that the prices paid to Sargeant were not reasonable because “no one else could transport the fuel through Jordan.”