The Plextor trademark has always been associated with solid solutions in the SSD industry. It has never been involved in a race of decreasing the price at any cost. That is why Plextor M3 and Plextor M5, even having not the lowest price, were one of the most respected among users and quite widespread models of storage drives.
Up to now, Plextor has noticeably lost its popularity, but in general it continues adhering to the old policy: the usage of expensive components and fixed hardware platform.
Plextor S3C was officially announced within the Computex 2017 tradeshow and at the same time it was deployed at retail.
Of course, it's impossible to refuse to participate in the race for price reduction completely. So the hardware platform developed by Silicon Motion on its SM2254G controller was taken (it should be mentioned that the first lots of the Plextor S3C were based on the SM2258G), to which TLC NAND was taken too.