You can get cheaper prices out of London, e.g. in Chester in Cheshire where my wife's mother and sister live. 

This Chester firm makes suits for Liverpool FC - http://www.distinctiontailoring.co.uk/full_bespoke.html A fully-canvassed 2 piece suit, made in their own workrooms, starts at £750. The founder's father had 40 years bespoke experience and ran his own firm

Cheshire Tailoring, also in Chester, starts at £650 - http://www.cheshiretailoring.com/

Crichton, a former London shirtmaker, is now based in Chester has expanded into tailoring - http://www.crichtonbespoke.co.uk/

Steve Whalley, who ran the Chester Barrie factory shop, uses his former colleagues - http://www.srwtailoring.co.uk/

I believe that Beno Dorn, a well established bespoke tailor in Chester, has similar prices. A trainee cutter posted on the London Lounge.

Chester is only 2 hours from London by train and you can get very cheap rail tickets by booking in advance. Just a thought.