1 pointW204 parts are not really “expensive” especially for routine wear & tear replacements. important is to get a reliable workshop that you can work with. i had a Honda but that was 28 yrs ago so no comments. My first MB was a 1977 W123 200E i m on my 9Th MB with some Audi in between important for you is to get a reliable workshop to check the conditions of the car, do a full diagnostic run & validate the odometer reading (can't run away with the diagnostic checks)
1 pointCheck the timing cam. It will be ratting during cold start if it is bad. W204 C180k is generally a very reliable car with accessable parts. Wear and tear parts to replace are radiator hoses, bushes, engine mounts..
1 pointMy Bro has renewed his 2009 C200 (PI) last year. His mileage was near to 200k km.