Brumby
Major
You're ignoring the fact that all of these costs are paid in Russian Rubles, not USD or EUR. The R&D work was done in Rubles, the manufacturing work was done in Rubles, and Russian raw materials were bought in Rubles.
It turns out Obama's bright idea of pressuring the Russians was a terrible mistake from that perspective.
The reason newer generation planes are getting more and more expensive is because the cost component is increasingly dominated by technology and electronics. Cost of electronics in particular are driven by global pricing and you get what you pay for in terms of quality. There is no local competitive advantage just because you are paying in rubles. In fact the effect is the other way around because as rubles depreciate against the major currencies, local cost is effectively going up. A 5th generation plane is dominated by technology and electronics and the idea of a $50 million pricing is devoid of reality. There are even talks of pricing the JF-17 Block 3 at that kind of level.
IMO, the idea of exporting the SU-57E is just Russian propaganda and the marketing spin will for go on at least for another 5 years. I don't think the Russian even have a finished product that they can export, or able to produce in a volume that can be competitively priced. .