District 9 cost 40 million and had nobody of note in it. It was a pretty goddamned weird sci-fi movie and people still went and saw it.
I don't think the conventional wisdom that says you need to a) be super-fucking-expensive and b) you need recognizable stars to sell a strong concept is all that valid anymore. People don't necessarily go to sci-fi movies because there are famous people in it. They go because they look cool/interesting.
Ghost in the Shell doesn't need to cost 150 million to work. And it doesn't need Scarlett Johannson to pack seats. If you exceute the story well enough, people are going to show up anyway.
Plus we're getting closer and closer to a day where audiences are going to automatically side-eye why white people are being cast as Japanese people in Japanese stories set in Japan, and that's going to start hurting box office as more and more people call "bullshit" on the face of that sorta thing.
One might argue that's part of the reason Exodus faceplanted - but I'm not sure that played as much a role as the fact it just never looked interesting in the first place.
But then again, that goes back to my initial point: So long as you realize the world you're playing in, and you execute the story you're trying to tell, (and marketing doesn't fuck the dog) general audiences are going to come to your movie regardless who the fuck is in it.