You haven't done tutoring before but you are a qualified experienced teacher, so don't sell yourself short.
My friend isn't a teacher, and I know he gets paid a lot for tutoring - just asked DH and he reckons he gets paid about $50 a session

He does work in an affluent area of Auckland though.
At Kip McGraths where I worked for a short while, they charge $42 per lesson (80 mins), and the student is one of about 3 in a group.