London garage sells for £251,000: why?

A double garage in Ed Miliband's stomping ground of Highgate was sold at auction yesterday for an astonishing £251,000. That's £80,000 more than the average house in the UK is worth, and three times the guide price that the auctioneer had put on the property.

So why did it fetch such an incredible figure, and what does this mean for the housing market in the UK?
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