I know a maths/11+ tutor who does OK in early-retirement from teaching (he's early 50's). He charges £40 per hour but he runs it as a proper business, so it's not just an hourly rate in his pocket.
He does Saturdays and Sundays throughout the year and adds in a couple of mid-week full days during school holidays, i.e. Summer and Easter. He also does late afternoon and early evening on some school days (2/3 per week).
Summer holidays are reserved for 11+ tuition. Easter/Christmas holidays are reserved for GCSE and A level Maths tuition. Mid week are a mix of 11+ and Maths GCSE/A level according to who he's got on his books.
He is highly organised. To avoid time wastage and travel costs, he hires a room in a church hall so he sets up his "classroom" and then sees one pupil after another so very little "downtime". He has a fairly strict, old school, style, with quite formal lessons and then a couple of hours worth of homework/practice after each lesson. There's no friendly chit-chat with him - he's right down to business so you really get a good hours' worth of one-to-one tuition. He doesn't take prisoners, he's more than willing to drop a pupil if they don't do the homework and he's quite honest (abrupt) if he doesn't think a pupil is up to the standard needed to get a high enough mark in the test.
For your £40, he provides the materials, mostly photocopied worksheets etc. but he also uses some proper text books and workbooks, and also marks the homework he sets, between lessons, so probably another 15 minutes on top of each one-hour tutoring session. So really, it's 1.25 hours of his time, plus a hour of room rental for your £40!
He also does group mock exams for GCSE, A level and 11+ where he hires a church hall, sets it up with exam desks, and does a proper mock under exam conditions, then marks it and has an hours' feedback/review lesson afterwards.
Despite his fees being on the high side and despite some people who may not like his old-school style, his books are nearly always full and he never advertises - all his business is recommendations/referrals.