I've budgeted for 55 hours in a PA-28, so I reckon about £7.5k. That's including all of the essentials, excluding luxuries like my headset.
One thing you've missed out is the Class-2 medical. The cost of that varies a lot (around £100 up to £300), so shop around. You need it before you can go solo.
Andy's right though - the money will keep flowing out after you get the licence. Next year I'm looking at 40 hours plus an IMC, so another £6k or so....