Given how tough the marketplace already is this summer for sequels, I expected a lot of controversy over the weekend box office prospects for Fantastic Four: Rise of The Silver Surfer. And is there ever. My box office gurus tell me they expect the Fox comic book caper to make $50+ million in gross receipts from its 3,957 theaters. (That’s less than the original, which took in $56M from 3,619 after opening; it went on to make $154.6M domestically and $175.4M overseas for a total of $330.1M.) But I’m told Fox execs would faint if Silver Surfer got to that number and they don’t think it’s possible. “Not in this summer. It’s a tough market. If it does Ocean‘s numbers, they’d be thrilled,” said a source, referring to the $37 mil that pic made last weekend. Also explaining the wide variation in numbers is that the movie skews young, and they’re hard to predict this summer. The studio keeps claiming it kept the cost down to around $125 mil. That’s rare to have a “1” in front of it, instead of a “2” or a “3”, like most of the tentpoles so far. Meanwhile, my film financing experts agree with Fox’s cautiousness: “The tracking reflects an opening consistent with lower-level Marvel pics,” an insider emailed me. Meanwhile, look for a lot of noise about the comic book company Monday when The New York Times kicks off the week with a big business section story about Marvel Studios.