The paper investigates the differences between transaction and offer prices for owner-occupied residential property in Hamburg. The analysis is based on two different data sets for the period January 2007 to March 2014. The list data are from ImmobilienScout24, now the biggest online market place for real estate in Germany. The transaction data were provided by EUROPACE, the biggest German market place for financing products. Both data sets are exceptional in their market coverage and have been combined in a specially developed procedure. The analysis reveals an average discount of 6.7 per cent for the 1,766 properties in the merged data. However, the discount is considerably reduced in phases of increasing prices and demand with the result that some properties are sold at even higher prices than those initially offered.