Housing is dear in London, but $60,000 for a broom closet? That was the asking price for a 5 1/2-ft. by 11-ft. room on Princes Court opposite Harrods department store in the affluent Knightsbridge section of the city. Though the cubicle had indeed been a broom closet, it was gussied up with a concealed kitchen sink, Laura Ashley wallpaper and a tiny window.
The astonishing price tag drove home just how superheated London's upscale residential-property market has become. The reason: a recent influx of cash- rich foreigners, most notably Arabs and Americans, and well-paid fugitives from the so-called "stockbroker belt" south...