Mandatory JVAC inspection/repair - are these costs off?

[Eric Sanford]

I've had my duplex's 2 boilers inspected in years past, it's been ~$250.  This year I mentioned during scheduling I needed the city's HVAC safety inspection sheet filled out.  After inspection, the invoice came at $560, same vendor.  Plus work orders for break down/clean boilers, trap combustion duct changes, and a new chimney liner, at $5950 for all.  These costs all seem high (and more than double for the inspection this time), plus suddenly a bunch of changes/repairs that never come up other years, now that I have to fulfill the city's inspection?  Thoughts?  Is the inspection portion just a coincidence, or are they taking advantage?  Are these items/costs normal (especially the $1500 per boiler cleaning), and I've just never run into them before?