I was under the impression that E25000 (approx £20,000) is required in five phased installments payable to FTE. Upon joining AL your are on a bond. Now whether that means a bond to repay the company through means of employment at a reduced salary or a bond to refund the money AL has invested should you leave early I am unsure...
However looking from PJN it would seem that there is a sacrifice of salary upon employment as a 'cadet'. But this could be outdated. Officer Kite can you say where you have found this information from?
In any event the selection fee is a small amount in the grand scheme of things.