Fox is already known for overpricing their Blu-Rays... I can only imagine what they will do with a much anticipated box set like this for all the enthusiasts out there that will pay anything to get their hands on it at first. I haven't heard if they are releasing the films individually at the same time which to me indicates they plan on maximizing rapage of fans first, then release the single films at a later date for a more moderate price.
Who knows for sure, but I don't have a lot of confidence in Fox when it comes to pricing. They milk everything.