Coastal point defense fighter does not make any sense to me. Against a potential opponent, all they need to do is destroy the bases. If you want to be able to defend your bases, it is better to put them inland where you can layer it with SAMs after SAMs as you approach the base. Bases near the coast aint going to get this protection.
Another point is that the FC-1 isn't cheap anymore. It has been so upgraded and upfeatured that I don't see a light price tag anymore. The engine isn't that much cheaper than the J-10's, 2.85 million for the RD-93 vs 3 million for the AL-31FN. Producing the FC-1 and reducing the number of J-10 as a result only results in increasing the costs of the J-10s. This means in the end, you won't be saving money as a whole, and your capability is lower.
It all depends in the end, how the FC-1 performs. With all the upfeatures, it may actually perform better than we expected it to be. The final determinant would be the PLAAF. I am pretty sure they would test and match these aircraft with other types in mock air combat, and whatever results they get, they will accept or not accept the aircraft by the results.