Complex sentence: The growing popularity of the book eventually changed minds at Paramount about the film's prospects; they raised the budget to $6 million and approved period filming on location in New York and Sicily.
Split into simpler sentences: The growing popularity of the book eventually changed minds at Paramount regarding the possibility of the film's success. The studio revised their original conditions by raising the budget to $6 million and approving on-location, period filming in New York and Sicily.