Here in the Bay Area I've been quoted $800 to clean a dog's teeth.
The affected teeth got loose. We pulled them. The dog is happy and healthy. I would have liked for a professional to have done that for us in a more controlled and methodical manner, but there's no way I could justify spending at least ten thousand freaking dollars on a 13 year old dog who was at significant risk of dying on the table.
I love my dog and spend pretty freely on him, but no way is he getting an $800 teeth cleaning. At that point, you might as well locate your practice on the airport and cater only to people who fly their dog in on a private jet.