Our school pays £30/ hour flying and £30/ hour ground school. As an instructor you need to be savvy enough to charge for ground school. As a student you need to be savvy enough to pay it.
Eg a good 30 minutes pre and post brief plus 50 minutes flying is cheaper than no brief and 1 hour flying. The instructor makes more money and the student gets a better experience. At many schools since the instructor is only paid for flying the briefing is done in cockpit at £ 3 or 4/minute which is massively inefficient.
I think a lot of instructors In the UK can’t get their head around charging for time when the engine isn’t running. But if my plumber charges £60/ hour for his expertise when his/her engine is not running why oh why aren’t we charging £100/hr for ours.