An 18-unit apartment complex in Winnetka has changed hands for $4.53 million, or nearly $252,000 per unit. The sales price for the Chateau Winnetka, at 7315 Winnetka Ave., is one of the highest per-unit sales prices paid in the Winnetka multifamily market, according to real estate data provider CoStar Group Inc. The seller, Domino Realty of Beverly Hills, purchased the complex in July 2014 for $2.9 million, or about $161,000 per unit, and completely rehabbed it before selling last month to private buyers Varant and Sevan Markarian of Glendale. Melinda Russell, a broker in the University City office of CBRE Group Inc., represented the seller in the deal. The property got a boost from its proximity to Warner Center and the recent upgrades, she said. The 17,600-square-foot property was built in 1985. Over the past year, it got new landscaping, a new lobby and common area interiors, as well as upgraded kitchens, floors and window shutters in each unit. “Vacancies in this higher-quality building rent very quickly, serving as a more affordable alternative to the Warner Center market, where unit prices and rents are substantially higher,” Russell said.