I know a guy who is a fantastic teacher. His website is: piano lessons london
I have just visited the link. The teacher in question is a 31 year old pianist called Georges Sokol. He graduated from the Conservatoir in Aix-en-Provence and obtained a diploma from the Royal College of Music.
I then checked out his entry on musicteachers.co.uk and was shocked to see that he charges £110 pounds an hour (175USD).
Have you had any lessons from him? I wonder what actually justifies this exorbitant rate. To put things in perspective, according to a survey by the Incorporated Society of Musicians, as at September 2010, the average charge out rate of a private piano teacher in central London with over 15 years of experience is £35, with a "central range" of £25 to £51.
I also know from recent personal enquiries with the Guildhall School of Music (August 2011) that there are piano professors there that are keen on teaching private sutdents (even amateurs), and they typically charge about £80 pounds an hour (which is not cheap of course, but at least justified by their professional experience).