IT IS widely acknowledged that Kingfisher wants to buy out the 45% of French DIY group Castorama that it does not already own. This would cost around £2.5bn and the retailer, which includes B&Q and Comet, does not have the money. Lateral thinkers in the City reckon Castorama should buy Kingfisher's stake for around £3bn and the money be returned to Kingfisher shareholders. Under a complex structure agreed at the time of the Castorama deal, the French group incorporates B&Q. A buyout would therefore leave Kingfisher as a pure electrical retailer, principally owning Comet here and Darty in France.