I love my equine dentist, but he is also a DVM. I would not have a dentist that was not a DVM. The dentist that is coming to you tomorrow should be a DVM if he is sedating your horse. If he is not a DVM and he is sedating your horse it is against the law to administer meds without a license. So run if he wants to and is not a DVM. Sometimes a dentist will bring a DVM with them to sedate the horse.
The $75 might sound cheap but sometimes that is just the beginning of the price, sometimes a dentist will charge for every little thing, i.e. $30 for a wave, $25 for a bit seat, $40 for points, $100 for an extraction, can add up fast.
I think most of the problems dentists get into are the material the drills bits are made of, I think they should be made of porcelain, I think.
I would look at how many drills your dentist has, does he have only one drill and has to change bits all the time? Sure sign of a beginner. My dentist has about 10 drills and each one has a different bit.
In this photo all the green and yellow hoses are connected to his dills and bits, he charges $175 for everything including sedation.