David,
There is a microlight instructor shortage now!!
(In my view, it all boils down to 800 hours times the hourly rate, minus expenses and VAT. So at 100 an hour, you have 80k to pay for aircraft, fuel maintenance, insurance, building, hangerage, publicity, phone, light, heat, office, personal at desk etc, etc, etc)
Hence, not a lot left in it for the instructor.
My thoughts (and actions) are £35 a flying hour for instructors in school aircraft, £70 an hour for those in their own aircraft.
As a result, I am the most expensive microlight school in the country, at £110 a hour for lessons.
(and on weighshift microlights, you are lucky to do 500 hours in a year!)
Very best,
Colin