While I applaud your enthusiasm, $2.87 Billion is really big money in the context of the DoD budget. Our Battle Lab in the Marine Corps had a budget of $25M per year and we made that money work very hard to innovate and develop useful things.
DARPA was an entity I worked with occasionally and competed with often. As I said before, they were very light in anyone with military experience or maybe even had seen a war movie. I will take your word that DARPA spearheaded things like the Predator and the internet but they have also wasted huge amounts of money on things that failed miserably when they hit the real world. They also count on getting industry involved early, which doesn't do much for saving money.
My personal favorite was Non-Line of Sight Missile (NLOS-M) which featured a set of small missiles, arrayed vertically in a shipping container which were meant to be used as precision fire support. The idea was that the forward observer would transmit the target grid, the missile would be selected and fired straight up, then orient towards the target and fly briskly to hit it.
The part they missed was 1. small missiles have small warheads and small warheads just make the enemy mad. 2. Things fired vertically from an enclosed container have recoil - so mounting the container on a HMMWV was a non-starter and if they lose GPS lock on launch, they come right back where they started. 3. Containers without wheels stay where they are set down - a disadvantage if the enemy changes locations. 4.Little missiles take a long time to get there if fired at long ranges. Nine minute times of flight require an enemy to stand still for an unreasonable period of time. And 5. Little missiles cost more than a quarter million each shot. Not supremely cost effective: however big the defense budget is, we don't have that much money.
Like I said before, very little real-world expertise, huge budget. Would be a lot more efficient if the services expanded their battle laboratories and had responsibility for R&D themselves.
I guess your view of the size of their budget depends on your frame of reference. To me yes $2.8 billion is huge, but the entire military budget is over $600 billion.