London auction houses are selling 16 million pounds ($26 million) of Asian art this week as a record number of buyers from mainland China flock to Britain. These newly wealthy collectors are buying at the highest level. By Nov. 3, west London dealer Marchant had sold 21 of the 54 pieces of Ming-dynasty porcelain it was showing. The star lot at auction so far was an Imperial jade seal that fetched 3.6 million pounds ($5.9 million), six times its top estimate, at Sotheby's.