Alex Sapir’s Sapir Corp. sold the penthouse at its luxury oceanfront condo building in Surfside for $33 million, marking one of the most expensive condo sales to close this year. A private equity executive paid cash for the 7,681-square-foot triplex condo at Arte by Antonio Citterio at 8955 Collins Avenue, which is record-breaking in Surfside at about $4,300 per square foot, Sapir said. The Wall Street Journal first reported the deal. The closing adds to