My last trainer charged me 30 for an hour private lesson. It was probably more like an hour and a half to 2 hours though. We would tack up the horse, she would lunge it, I would get one, do some lunge work, ride off the lunge, canter on the lunge, cool the horse off, then sometimes me and my friend (who was my trainer's daughter) would go riding in their pasture. By the time we got back and the horse was cooled off and sprayed off, it would be about 2 hours.
I live in a small town though. Mrs. Nancy had a four horse barn, with two of the horses being 3, and not lessons horses. She refused to have two people in one lesson. She was a great trainer. It was really just a hobby for her, not a job.