Paradise Valley, Arizona, just got a double feature. Two neighboring estates on N Casa Blanca Drive — each with big-square-footage living and serious outdoor programs — have launched for sale and can be purchased individually or assembled into a $28 million multi-home compound. The headliner, 6215 N Casa Blanca Drive, is listed at $17,500,000; next door, 6209 N Casa Blanca Drive is listed at...