Shilao had brought up something on a show in late 2024 that supported your estimate here of cheaper by 20%.
PLAAF leadership really pushed Shenyang to hit a per unit cost of US$80 million for the J-35A variant due to how foreign media reported the per unit cost of the F-35A being that much, but they did not account for the additional US$20 million of the F135 engine required that brought its flyaway price to over US$100 million in reality.
PLAN in the other hand did not have such tight budget concerns, as they went for higher specifications on internals with more bells and whistles since they would likely be purchasing fewer numbers of the J-35 navy catapult variant in total.
Furthermore amongst the four main services of the military not counting the PLARF, only the PLAN has the possibility of fighting a peer military without much support from the other services in distant shores and with limited numbers of fighter jets to fight with operating from its aircraft carrier battle group.
Carrier based fighter jets would also get much less organic support from early warning assets compared to J-35A operating directly from land bases too, so the PLAN would prefer to maximize capabilities of their carrier based fighter jets even if as tradeoff naval J-35 costs per unit would be higher and perhaps reach the prices of the F-35C.
