Well thanks everyone for the many view's, but 27/09 is right. The school has a limited number of spots available, and I'm sure that they want the top students so they stay right through to their CPL so the school can get as much money as possible.
As for payment, essentially the government pays the flight school through the student loan scheme and then I pay the government back, and the government only pays them as I go, not as a lump sum up front, so hence the reason they would want to get the top students who are likely to succeed and not get the one's who will drop out. And as for the school itself, It has a good reputation and has been around for a while.
Thanks for everyone's input