By Pat Bramley, property writer This house in Stanley Hill Avenue, Amersham, had an asking price of £2,750 a month New figures released this week provide an insight into the scale of the mass migration of Londoners swapping life in the city for a home half an hour’s journey on the Chiltern Railways line from the green, green pastures of Bucks. Over the first three months of this year, potential buyers adding their names to Savills books in Amersham and Beaconsfield increased by 70 per cent, based on figures 12 months previously. Over that period sales agreed at the two branches soared by a whopping 158 per cent. Sales to London buyers rose 80 per cent.