Monkey Wrench Plumbing Co

Sometimes you gotta shake your head at the sheer gall of some people. Are they simply completely lacking in any degree of ethics/​morals or are they just deluded and think everyone in the world but himself is a moron?
When the tankless water heater began to leak, my tenant got this clown joint’s name from the Noritz website. The technician (ie highway robber whose name starts with R) came and incredulously with a straight face quoted $ 1795 to replace the heat exchanger/​isolation valves and the filter. OMG. ARE YOU CRAZY?
The exchanger, mind you, is still under warranty and HENCE FREE. The valves are $ 75.
So this is his rate for labor?
Then as with all sociopaths, he just cannot stop. He goes on to say tankless heaters lasts max ten years. This is very different than the 20 years I’ve been told by everyone else. He goes on to suggest my 8 year old heater can be replaced all together for a mere cost of $ 5698. A similar brand new tankless heater sells online for $ 1200. .
This guy must have some skills to warrant those labor prices.
To put this into context, I of course then turned to Unilocal.I call and discuss the problem with another highly Unilocaled plumber (Curtis Watanabe) who says changing out the exchanger is standard for a skilled technician, should cost no more than $ 250. Another plumber (RH Plumbing) quotes me $ 800 MAX for heater installation if I were to replace it.
I am waiting for the written estimate from this rip off artist so I can forward it to the BBB.