Like everyone else said, millions of dollars.
Look at it this way: there's the salaries of the civilian flight instructors (which were raised a couple years ago to actually entice people to live voluntarily in southern Alabama), salaries for the academics teachers, maintenance on the aircraft, new parts for the aircraft, buying new aircraft, fuel, upkeep on the airfields and stage fields, emergency vehicles, people to man said vehicles, maintenance on the emergency vehicles, the list goes on and on.
Jet A1 fuel is currently running about $7/gallon. Each student in a class of about 30 flies maybe 80 hours in the training aircraft burning 20 gallons an hour before moving to their advanced frame and flying 60-100 hours burning... call it 35 gallons an hour as an estimate. I'll let you do the math, and that's just for fuel.
So how much money goes into training a pilot? A LOT