A Portsmouth penthouse condominium sold for $5.825 million, topping the list of highest-priced condos and single-family homes in the Seacoast in September. The three-bedroom, four-bathroom condo at 233 Vaughan St. set the record for the most expensive condominium sold in Portsmouth, according to the Seacoast Board of Realtors. The 4,256-square-foot rooftop unit has views of the downtown area, the riverfront and neighboring Kittery, Maine.