Everything is relative, F-35 and J-20 which are also currently under development (and in F-35 case a lot longer) didn't show anything impressive in terms of flight performance, like whatsoever. After only 5 years of development T-50 I thought demonstrated quite great program at MAKS 2015 (which also shows fairly strong confidence from designers). And I'm sure there were still some G restrictions set. Also do not forget there is still room for grow with 2nd stage engine.While you are partially correct about the MAKs performances, my impression is that they are less energetic than the SU-35, F-22 performances that we have seen. More importantly we are seeing a very limited spectrum of the T-50s flight envelope.
I don't know how you come up with this stuff. 250, 000,000? That number is as realistic as 0.0000001 RCS of a certain fighter. Yeah, Russia will buy only 12 and then I guess will close the program. Sounds realistic. They will buy as many as they can build. And how many they can build will depend on economic situation and industry potential (they surely can't produce them at the same pace as Americans for example). Here is Victor Bondarev's inteview about this:one of the reasons the Indians have become insistant about flying it, if the Russians have cut their buy to 12, that would indicate that it may not offer any real world advantages over the SU-35?? Certainly not enough to justify the T-50s 250, 000,000 price tag?? that's nine figures?? that is a bunch of cash.