In Kentucky there are approved vendors of these devices by the government. I do not know for certain, but I assume if they had outrageous pricing, they would no longer be approved.
Why not? The minimum court fines and fees and programs are often outrageously priced themselves. A 3 hour "Dont drive impaired" program with 30 people on it can be up to $1000 per person. What other service can justify a $10,000 an hour price tag?
It is $80-90/month in Kentucky, with a $40 starting fee paid to the Kentucky's DUV. So you assume incorrectly; their "approved" vendors are the same as most other states.
I'm legitimately quite confused about this reply in general, why did you assume I wouldn't be talking about a state like Kentucky? Did you consider that most states/courts mandate approved vendors?