Vetflyer
"Especially why clubs charge approx 4 times what i get paid for private hire ie no overheads."
True, but it's not quite that simple. The school will have to likely pay to be at the airfield, mostly, and so in the overall business plan will have to charge more than just the instructor fee. Also, in theory, that would mean that if every student turned up in their own aircraft and the school charged only the instructor wages they would earn no £ and that would mean no school = no instructor. The school in some cases will be paying for their buildings, electricity, phone calls to arrange the flight, reception etc etc etc. That's business, not as simple as "no overheads".
Now, whether it needs to be 4 x the instructor fee is of course debatable, but depends on those overheads.