welcome to reality.
We have created a society of parts replacers. ASE techs are taught to read gauges and swap parts. Very little dianostic understanding is necessary. Ethics and honesty are long gone from most shops. Ancient techniques such as carburetors are dying with the old timers who have gone into seclusion. Think not? How many rodders on this site put a carb "right-out-of-box" on an engine, it doesn't run right, so it is the carb manufacturer's fault?
Finding ethical and knowledgeable technicians is a trick in itself. Look for an old guy under a backyard garage roof.
example. I have a friend with a 98 Chevy conversion van and two completely separate A/C systems, two compressors. Both AC quit at the same time.
The new car dealership that sold it and two other shops say that it will cost $ 2000+ to repair the AC systems, maybe more if they find more bad parts.
Question is....... Why did both AC systems quit at the same time as the DVD, radio, and TV?????
The techs cannot be THAT stupid, can they?
Can you spell RIP OFF?