Without changing a single aspect of the job other than paying £30k you would removed 80% of the problem
Personally, I agree with that - although not with WWW's reasons. If you were to pay instructors £30k, then a whole load more people with a genuine interest in general aviation, and in instruction, would apply for jobs, or would stay in the job longer. Those who never really wanted to be an instructor in the first place would probably not think to apply, or if they did they would (hopefully) not get through an interview.
Just my opinion.
FFF
-------------