Koreans are cheaper to service since they dont really check much. Just simple oil change. Of course, Im saying this based on Hyundai Sonata which I sent to authorized SC to service.

As for parts, they are still slightly expensive for common parts like bumpers, headlight, tail light, etc. However when it comes to rare parts like windscreen, sunroof, etc, the figure start to fly over the roof. Sonata windshield cost 1.8K while Camry cost RM900 (IIRC). One might argue that some Koreans part are higher quality like with DRL, projector headlamp instead of reflector on common Toyota and Honda or windshield that came with rain sensor. However you do find rare occurrence where Koreans are cheaper to maintain when it comes to accessories. Usually if you had problem with Honda/Toyota side mirror LED etc, you had to change the whole unit. Koreans had the LED only module.