Hi
A lot will depend on how competent you are as a student and how good your instructor is. I spent £9500 to gain my ppl in 2012 and it took me 65 hours to complete. I struggled with my landings in the beginning and to took a lesson with a different instructor one day who taught me a slightly different approach and suddenly I got it. I'm not suggesting that my instructor wasn't any good but it cost me about 5-10 hours of instruction!
Other costs that some schools don't tell you about is the flying test fee (about £350) and once you pass the fee to the CAA for your licence (£185) and your class 2 medical (up to £200 so shop around).
As Thing says you also need to budget after you gain your licence. Many clubs insist you fly at least once a month to stay current (approx £175 a month), club annual membership (mine was £180 pa), bi annual medical (£200) and on top of that landing fees and lunches on your days out. Yes it is cheaper if you split the cost when you take friends and family out but it is still an expensive hobby.
Another factor to consider is what you want from your licence. Are you going to go further with a night rating, IMC rating, full instrument rating etc. all of which will require more money.
I have to admit that I didn't think beyond passing my skills test and getting that licence and have struggled to fund my flying so much so I am now flying microlights as they are cheaper at £118 an hour and in my opinion, more fun to fly.
I don't want to put you off because becoming a pilot is the greatest thing I have ever done and there is nothing like cruising around at 2500 feet on a summers evening watching the world below you. The bottom line is there is no fixed cost in gaining your PPL but one thing is certain, once you start flying you won't want to stop.
Good luck