The Hellfire is not an ideal fit for the Predator, David Hambling notes (in Swarm Troopers), which struggles to carry two of them:
Rather than developing smaller, smarter weapons, the Air Force decided it wanted a bigger aircraft. General Atomics anticipated this and the company funded development of “Predator B.”
[…]
When it went into service in Afghanistan in 2007, the Predator B was renamed the “MQ-9B Hunter-Killer” or “Reaper.”
[…]
It is four times as heavy; the turboprop engine is six times as powerful and doubles to speed to around 200 mph.
[….]
A Reaper can carry fourteen Hellfire missiles, or four missiles and a pair of laser-guided 500-pound bombs.
[…]
The flyaway price for Reaper is around $14 million for the basic model, or $20 million with all the trimmings, compared to $4 million for a Predator.
[…]
So instead of a cheap, ultra-long endurance, expendable drone, the Reaper resembles a manned aircraft. Predator operator Matt Martin describes the Reaper as “a longer-duration, lightly-armed (and much less survivable) version of the F-16.” Without the duration and price advantages, the Reaper comes perilously close to being in competition with the manned jets. As we have seen, this is often a fatal situation for a drone in the Air Force.
It’s just possible the best weapon has the highest price tag. Just.
Not that this had anything to do with the $20M price tag. That’s pure $$.
As the Elon observed that the ideal formula in space was dollar cost per unit mass to orbit, the ideal formula in war is dollar cost per unit destruction to target.
The USAF brass should read Kill Decision by Daniel Suarez.