From elsewhere at the Guardian, Benji Lanyado:
For years, London has been touted as one of the world's most expensive cities. But a recent survey shows that its rip-off reputation is slipping. In a Mercer survey measuring the comparative cost of over 200 items in 143 cities, London dropped 13 places to number 16 in the world, falling below Paris, Hong Kong and Geneva...Amazingly, the survey even claims that visiting London is better value than a trip to Caracas, the capital of Venezuela.
This comes as no surprise to Benji, who has many suggestions for enjoying the capital on a budget. You can explore the Mercer data here and here.
Update, 09:42 You can even buy a book by the Mayor for next to nothing. HelenOnTheBus has texted to say she's just spotted a copy of Life In The Fast Lane in Poundland.