Almat at EGBE are charging £98.98 dual and £79.00 solo on a rather old C150's, so if Glynn is generous enough to pay the instructor the difference between dual and solo, for instructional flights, thats £19.98/ hour.
So based on an average of 3 hours flying a day thats £59.94 a day or based on an 8 hour day is £7.49, dont forget you will be self employed, so after tax, national insurance, medicals, insurance, security pass, parking, renewals, travel, your guaranteed to fall below the minimun wage!
This is the reason why some schools are unable to find instructors!