Did the school concerned give you a breakdown of that price?
Reason I ask is that that some schools will give you minimum costs (i.e. min hours in the cheapest trainer) and may forget to show you how other things like medicals, exams and licence fees can add up. In this case, it's possible the school was giving you a realistic budget figure - allowing for extra hours above minimum (which is common due to waiting for weather etc) and including the 'peripherals' like books, kit, medicals etc etc.
My initial feeling is that £5500 is a little tight for a PPL in southern UK - I would budget nearer the £6000- 6500 mark if you can - I'm basing that on doing around 50 hours for £120 per hour.
Best of luck - you won't regret learning to fly no matter how much you spend!