Hollywood studios are now thinking twice about splurging on A-list movie stars and costly productions in reaction to the poor economy, but also because of the surprising success of recent films with unknown actors. After buddy comedy “The Hangover,” a movie with a little known cast, made $459 million at global box offices this past summer, several films have shown that a great concept or story can trump star appeal when it comes to luring fans. “District 9,” a low budget movie in which the biggest stars were space aliens treated like refugees and the lead actor was South African Sharlto Copley, made $200 million. Thriller “Paranormal Activity,” starring Katie Featherston and Micah Sloat, has cash registers ringing to the tune of $100 million. Next up, on Nov. 20, comes Summit Entertainment's relatively low-budget ($50 million) franchise movie “The Twilight Saga: New Moon,” a sequel to 2008 hit vampire romance “Twilight” which made global stars of Robert Pattinson and Kristen Stewart. Online ticket sellers report “New Moon” is one of their highest pre-sale movies of all time, and box office watchers expect the film to have a smash opening. “Nobody says that a big wonderful movie needs to be expensive, it's just that that's been the trend, and perhaps the trend is misguided,” said University of Southern California cinema professor Jason E. Squire. Last weekend, comic actor Jim Carrey's “A Christmas Carol” became the latest celebrity-driven movie to stumble at box offices, opening to a lower-than-expected $30 million. Aside from Jim Carrey and “Carol,” which cost at least $175 million, A-listers who suffered box office flops recently have included Bruce Willis (“Surrogates”), Adam Sandler (“Funny People”), Will Ferrell (“Land of the Lost”), Eddie Murphy (“Imagine That”) and Julia Roberts (“Duplicity”). “The (major movie) machine didn't fly last summer, if you look at the movies and the names, they were not star-driven movies, they really weren't,” said Peter Guber, chairman of Mandalay Entertainment and former head of Sony Pictures.