Thinking of buying in Martin County? Be prepared—it ranks as the fourth most expensive county in Florida for homebuyers, according to SmartAsset. The study used localized Freddie Mac data to calculate the true cost of financing a median-priced home, landing Martin County at No. 178 nationwide. Known for upscale enclaves like Jupiter Island and Sewall’s Point, the county also ranks as Florida’s sixth wealthiest. Beach-Homes.com, a premier coastal real estate site, reports that homes on Jupiter Island sell for over $11.5 million on average—making it one of the priciest housing markets in both Florida and the U.S.