I paid him £50 per flying hour or £200 per day
Sheesh, try charging students that. Nice work if you can get it but the reality for most of the time for most instructors is £10-20 an hour because schools know most instructors will do anything to build enough hours to get into an airliner right seat. The economics of aviation training stink and will probably never improve because (a) virtually all the instructors do instructing as a step to something else (b) most of the trainees are only learning to fly for fun and (c) as long as that continues to be the case the airlines won't put their hands in their pockets to pay for training.
NS