Checkout this price-guide.
Ceramic Solutions - Price List
I think there's a couple of ways to look at it and it's just really what you feel your customers want to hear. £5 per meter but lots of add-ons or £20 per meter without or a total job price.... it should all total your living costs and a bit more really. I doubt you'll ever see a millionaire tiler that's made his cash from tiling alone and traditionally you'd never see a broke tiler either.