I am not sure where you live, but there is a little salon in Land O Lakes called Salon at the Lakes. Rita, the owner, is really good. However, it isn't meant for kids and it is a little shack. Rita has actually sat on the floor to cut my childrens hair because they didn't want to sit in the chair. She even went out and bought a child size lawn chair so that they could graduate from the floor to the chair and now they sit in the big chair. She is GREAT. If you have a portable DVD player you could take it with you and put it in his lap - she wouldn't care. I think she charges $10 to $13 - not exactly sure because I have to pay for two and then tip. I think I give her $26 - which would make since if it was $10 per cut.
Anyway - I have managed a Salon before and my mom is a hair stylist, so I know this much - you have to find someone the child is comfortable with and someone that is comfortable with kids. Just because a stylist works in a kids salon doesn't mean they really like kids - it is just a job and the parents usually tip well because of the situation. So, my advise to you - find someone you think your son will like.
Good luck!