- you're not legally allowed to do more than share the costs with another pilot so you would still end up having to pay for the flying." I am guessing here!
Quite clearly! and mixing up regulations too.
The student pays for the flight, the aircraft is public transport so its quite legal to hire, the school get their cut, the instructor just doesn't get paid for the flight.
There are a number of PPL instructors; some traditional aeroclubs don't pay their instructors anyway.
The point is that the requirements to get a FI rating are such that there is often little point in not completing the CPL unless you really don't need it.
Microlight instructors operate on a PPL! and get paid.