Here is the scientific formula for calculating London’s top property prices: think of a figure, double it, add a few noughts, and voila! — or should I say nazdarovie, of whatever it is that oligarchs say when toasting a deal. Ordinary mortals nowadays are worried sick about their mortgage repayments, set to rocket when their short-term fixes come to an end and real-interest rates kick in. They lie awake at night with images of Northern Rock queues flashing before their eyes and wonder why Mr Darling, whose eyebrows failed to reassure over that issue, also failed to do anything for first-time buyers since taking office. But meanwhile, in a place far, far away, known as Prime London, property monopoly has turned into property porn.