A Weston Parkway office building in Cary that was recently vacated by growing-software firm SciQuest has been sold to a Charlotte investor group for $12.5 million. Real estate records show a joint venture partnership led by Charlotte-based Childress Klein Properties acquired the three-story building at 6501 Weston Parkway from a subsidiary of Archon Group , the real estate arm of investment bank Goldman Sachs .