I'm sure the U-2 requires alot of support for an operational sortie, but for a round robin training flight out of KBAB I don't think it really requires too much. I don't know if they carry all their intel gear on training flights. I'm sure they carry some of it, but probably not all except for ops checks. Add some crew chiefs, maybe some tech reps or specialists for the hush hush stuff, a PSD or whatever they call them now specialist or two for the suit and connections, etc. Then the crew to remove the pins from the pogo gear and pick them up after takeoff. Not many people. More than a fighter, but not an inordinately large group. In any case, this is probably another reason for the 38s. Just 1 or 2 guys as the ground crew and it's kick the tires, light the fires. The U-2's preflight is very straightforward from the pilot's view at least. I've heard Mx side is very easy too. At least for a crew chief cause so many of the systems on that jet are only handled by specialists. The flying pilot doesn't even do a preflight; his backup "Mobile" pilot does it so he can suck on 100% oxygen for an hour and not have to worry about flipping alot of switches and walkarounds and all that jazz.
I'm sure the U-2 has to cost more to operate than the T-38, but I'm guessing he might've projected something from the SR
-71 into the U-2 in that respect. That jet was VERY expensive to operate normally. Took something like 5 crew chiefs damn near a day to service, preflight, and launch it. Not counting the specialists to load the TEB, sensors, crew, etc.
Most prep time, I'd guess either the VC
-25, E-4 or maybe the E-3 or B-2. Of all, I'd say the VC
And yes, the U-2 carries hydrazine