After 3500/4000 km of ride almost overvolted, today I checked the planetary "crappy" gearbox of my Cyclone engine.
The gears still in very good condition, I simply cleaned up the gear and replaced the greease with the new one. I think that they will work for at least another 2500km without need the substitution.
In the photo you have the teeth are very worn out and pointy compared to new, they have also lost their ramp on the tooth profile hence i imagine it would be very noisy now and not much life left in them, if you had run them in an oil bath like AFT they would have lasted a lot longer. Also all those wear filings have being going into the steel bearings so they would have some consequential wear on them also compared to the AFT where they put magnets to suck up the fillings from the oil to stop going to the harder ceramic bearings they would have lasted longer as well. And yes you get what you pay for as you said and thats cheap wont last long.... .