A living room inside David Sullivan's London mansion.Knight FrankBritish billionaire David Sullivan has cut the price of his London mansion by about $13 million.The businessman, who owns the West Ham United soccer club, said he is taking a loss on the property.Sullivan is worth an estimated $1.6 billion.British billionaire David Sullivan has cut the price of his London mansion to £65 million (about $85 million), knocking about $13 million off of the previous asking price.Sullivan, an owner of the east London-based soccer club West Ham United, told Bloomberg that while he would now be selling the property for a loss, "you have to be realistic."A living room in the house.Knight Frank."Interest rates are high — they're coming down but not much," Sullivan said."I also think what the government is doing to the non-doms isn't very nice, and a lot of rich people are leaving the country as a result of what they anticipate in the budget.