coming to GOG? It'll come after Paramount, Warner Brothers, and the other major studeos bring their RECENT movies/top sellers here DRM free. As to watching without DRM, there's a tool for making that from a DRM'd version.........
As for the topic, the first 3 are up on itunes with NO RENT OPTION

You're actually making the better choice; a rental is all this movie deserves.

For sale no longer means also for rent, especially with Disney products. For example, nearly all the Marvel movies were removed from digital rental last year and didn't return until last week, when all the movies leading up to Civil War showed up on most major services (basically everything except Thor and GotG). I honestly wouldn't be surprised if SW7 wasn't available until a month before SW8 releases in theaters.

You could buy the DVD (if exists) or Blu-Ray, your mileage may vary, and it would act nicely. OR you can go to a friend who owns the movie on a DVD or Blu-Ray.

MakeMKV