Make sure you are comparing like for like. check what is included or not at each establishment, think about accommodation, CAA fees, groundschool fees, booksetc etc etc it does go on and on and on.
Also find out availability of course dates, aircraft, instructors. Best to find students/ex students to talk to as the schools will always give you what you want to hear. Then look at when they want the money - if they are asking for it all up front the quote will be a lot cheaper, but be vary wary about parting with your greenbacks before you have received anything. So, just to make you look at the right things when comparing, remember it is a minefield out there so get as many independent opinions of the school as you can before choosing.
Good luck, and yes it is very expensive, all in I have spent over UK£60k!
PP