Your numbers for Korea aren‘t correct. ROK ordered additional 20 F-35A (Dec. 2023) in latest block for $3.1 billion. But that deal also included costs for building a domestic maintenance, repair & overhaul depot.
So, way under $150 million a piece
South Korea is working to establish its own F-35 MRO depot at Cheongju AB by 2027.
aviationweek.com
That being said, until a fighter jet is fully developed, tested, mass produced and operated no outsider will know the real costs.
KF-21‘s unit price was estimated at $ 65 mil. but now first 20x Block I will cost per piece:
- $70 mil. per airframe & sub-systems (KAI)
- $20 mil. for 2x licensed-built F-414k engines (GE/Hanwha)
- $2 mil. for GaN AESA radar (Hanwha)
est. $92 mil. per unit for KF-21 Block I
Keep it mind, that all production deals also included partially development costs for the different systems, so the prices for later blocks will be much lower.