I think China isn’t buying Russian military goods because:
1. they’ve reverse engineered it
2. they’ve improved on the originals
3. can build it cheaper and with a better quality than Russia
Much like what they did with the Su-27 Flanker air superiority fighter. The Chicoms started building their own version, the Shenyang J-11B, with advanced indigenous avionics, and improved it to the point where it reaches that of the Su-35BM Flanker-E.
Same thing with the S-300PMU-1 (SA-20A Gargoyle) area-defense SAM system. They developed the HQ-9 and augmented a radar control system based on that of the Patriot. Now they're contemplating on exporting it to third world clients, such as Pakistan,, to bolster their air defense nets.
