Martin Roberts meets one of two young brothers busy building a property portfolio in Bolsover, Derbyshire, while Dion Dublin checks out a three-bedroom semi in Wolverhampton, and Lucy Alexander is impressed by plans to convert a two-bedroom, fire-damaged terraced house in London's Plaistow into a smart five-bedroom property. All of the houses have been sold at auction, but will any of the new owners manage to make money from their investments?