There are a lot of flaws in your scenario. First of all, out of the $700 million it makes for the movie, Sony isn't going to get all that. They'll get about $110 - 115 million from the domestic market. They'll only get $25 million from the Chinese market, and the split in other foreign markets aren't as generous as the US/Canada. Second, you use home video sales as if the market is as vibrant as ever. Sales of the first Amazing Spider-Man weren't impressive to begin with and the market is in a severe decline due to the transition to digital with services such as Netflix and Amazon on Demand. And with the negative reception this film has been getting, do you really think that sales of the sequel will be on par with the second? Third, typically a blockbuster film should be making its money back while still in the box office, not wait for home video to come and save it. This isn't like Kick-Ass or Dredd where a smaller budget film gets saved from total financial embarrassment due to great home video sales. And finally, "it's not too bad that Disney gets the film's merchandising?" Are you high? Because that's just absurd. Merchandising really, really helps a film out a lot to where a lot of times, it is just as important as the film itself. Just ask Disney as to why they decided to make Cars 2 despite the fact that Cars was one of Pixar's lowest grossing and rated films?