Harrison Ford and Calista Flockhart have put their 9,000-square-foot loft on Seventh Avenue in Chelsea up for sale for $16 million. The buyers would be neighbors with Meryl Streep and Janet Jackson. We hear they want to sell their pad because the upkeep ranges from $13,000 to $15,000 a month. They have a home in Brentwood, Calif., and an 800-acre compound near Jackson Hole, Wyo. Sources say they may be looking to buy a $12.5 million estate in Mandeville Canyon, where Steven Spielberg lives.