Communities and Local Government calculate monthly mix-adjusted average purchase prices of domestic dwellings bought by first time buyers based on data from the Regulated Mortgage Survey. This is available for the UK, by country and Government Office region back to February 2002 on our website at:
http://www.communities.gov.uk/documents/housing/xls/livetable592.xls
From the weblink given the average mix-adjusted price of a property bought by a first time buyer in November 2008 was £147,329 in England.