Simple, the retailer wasn't willing to allow the lot to sell at what he thought was too low (highest winning bids were in the £240 range) so he increased the bid to about £480. Some genuine bidders did go over that, and got themselves a very good TV, the others magically reappeared on another dutch auction a week later, and so on and so on, until the retailer has shifted all the units at a price the retailer likes which defeats the purpose of a 'no reserve price' auction.