The Chicago production of “Wicked” will close after its 1,500th performance next January. “By the time they fly away, the witches Glinda and Elphaba will have enacted their musical spells on more than 3 million people in Chicago over a 3 1/2-year run. And a production with start-up costs of about $10 million will likely have taken in a whopping $210 million at the Chicago box office.”