ermm, i've never had it done but you would probably be best asking around your local garages/quik-fit type places cos they should be able to point you in the direction of some people in your area, as they normally use other companies to do it for them
just went on their website at http://www.pristinealloywheels.co.uk/ and can't see any pricing but i THINK i had a quote from them before for a set of 13x5.5Js and they were by far the highest, about £60 a wheel if i remember correctly!
I guess it all depends how bad (or good!) your wheels are!
They are a little bit scuffed!! i have found a company called Lap Tab in the Midlands. Anyone used them before? I will try and post a picture of the Cinq for the world to see....