Here’s a tale of two movies.Supergirl cost $170 million to produce and had everything going for it: the backing of DC Studios and Warner Bros., worldwide distribution, and a marketing budget over $115 million. By year’s end, however, the film is projected to gross around $100 million domestic and a little over $200 million globally. When all is said and done, losses could be as much as $120 million. Iron Lung, comparatively, had nothing going fo…