£20 goes towards the general costs of providing a building, warmth, electricity, brief debrief time of the examiner that could be flying earning money. And in the future computer and phone internet access.
It also goes towards the cost of re-validating examiner privileges every 3 years as i am about to do. Roughly £725 plus cost of travel, aircraft fuel (aircraft at my cost as i own it) and lost income for day and a half.
I would not be employing a separate GR just to oversee exams, so i have to encourage candidates to sit on rainy days so i can oversee them, as i do now.
Also charging gives the student a sense of loss if they don't pull their finger out. I only charge when they pass, which has been totally wrong on my part. 1st sit i should charge and resit free.
Candidates could go elsewhere to do exam, such as a week course, they will be charged for course time and exam sits.
Flying schools are businesses, not charities.