Biggin
I used to instruct at Biggin Hill and although not familiar with the Cabair setup or instructors, i bet they are lot more expensive than the rest once all the extras are added on.
If you go past all the schools right up to the security barrier and say your going to the schools and follow the road, there are some smaller schools who are very personable and competive.
The main thing is that you are getting on with it with the summer on the way.
Regards