According to Official Guinness Records,
The world record for a clock sold at auction is £1,926,500 ($3,001,294) for a Louis XVI Ormulu-Mounted Ebony Grande Sonnerie Astronomical Perpetual Calendar Regulateur de Parquet, achieved at Christie's, London, UK on 8 July 1999.As part of the works of art from the collection of The Barons Nathaniel and Albert von Rothschild, the sale set a record for the highest grossing single-owner European sale at £57,716,497 ($89,916,528).
For a complete list of 1999 records, please visit 1999 Guinness Records in United Kingdom.