As demand for luxury apartments increase, developers are raising the bar. Sun Hung Kai Properties Ltd., the world’s largest developer by market value, raised the price of two penthouses in Hong Kong by 50 percent to a record HK$75,000 ($9,700) a square foot. The units will be offered for HK$300 million ($39 million) each, said Victor Lui, executive director of the company’s real- estate broker. They each have 4,000 square feet (372 square meters) on three floors, an outdoor garden and a swimming pool.