The movie trilogy “The Hobbit” has so far cost nearly three-quarters of a billion dollars to make as the epic continues to set new benchmarks for studio spending. Financial documents filed this month in New Zealand, where the films are being made, show production costs through March had reached 934 million New Zealand dollars ($745 million). That eclipses previous records for film productions. On a per-film basis, however, the movies are not the most expensive ever. At least not yet. Distributor Warner Bros. declined to comment.