The Monopoly edition you're referring to is the "Monopoly: The Classic Edition," which was released in the UK in 2000. This version featured the standard UK board with Mayfair and included pink Community Chest and blue Chance cards. All the properties were represented with dollar amounts using white notes, ranging from $1 to $500.
Mayfair
Mayfair
In Monopoly, the property that follows Mayfair in terms of value is Park Lane. Park Lane is the most expensive property on the board, and it is situated adjacent to Mayfair. Together, they form the most lucrative color set, the dark blue properties, which yield high rents when developed with houses or hotels.
mayfair
300
£400
Mayfair is the most expensive property in British Monopoly.
Boardwalk
Mayfair (not Mayfair Street) then Regent Street & finally Trafalgar Square.
Very much outdated but £400.
Mayfair
The most expensive property on the UK Edition of Monopoly is Mayfair, costing £400