When the RAF looked at NCO pilots recently during a planning exercise they worked out more expensive than officers over a predicted 20 year period (2016 figures used):
OR-6 Sgt starts on ~£35k and after 20 years as an OR-9 MACR earns about £48k
OF-1 Fg Off starts on ~£31k and rises to top of Flt Lt on £47k
After 2.5yrs the officer promotes to Flt Lt on ~£39k and the Sgt is either on £36k but promoted to FS about 3-5 years later starting on ~£38k. However, the 2.5yrs that the Sgt gets paid ~£4k more, and the MACR gets £1k+ per year towards the end of the 20 year period means that the NCOs are likely to be ahead by ~£20k over the period.
The RRP(F) is exactly the same for officer pilots as it is for the Army. They also get a retention payment of £70k but at a different point. So no savings to be had there.
Finally, an officer’s quarter is cheaper to the military as the officer pays more for a quarter than a SNCO will pay for theirs per month. Further, the SNCOs get free uniforms, so more money costs there. Plus also, most SNCO aircrew have the education quals for officer entry anyway.
So overall, SNCO/WO pilots worked out more expensive than officer pilots!
Not sure if the same applies to the US military, but it’s worth doing the maths (math!) first.