A 2-year-old residence on Casey Key has sold for $4 million, making it the highest priced residential sale in Sarasota County in September. The four-bedroom home has just over 4,000 square feet of space under air plus more than 3,700 square feet of outdoor living spaces. It originally was listed in mid-July at $4,350,000. Steve Wexler and Marty Benson of Premier Sotheby’s International Realty were the listing agents; Drew Betz of Keller Williams on the Water was the selling agent.