Cheap doesn't mean minimally viable. The story which the Director was telling was able to be told in a 'present day' simple way. There's no way you can tell the story of "Star Wars" without scale models, expensive cameras, good actors, and special effects.
However, even though Primer only cost a few $K to make, there was nothing "minimal" about it. The entire story needed to be told, and the process of filmmaking already includes editing and pairing down the story. I think that the notion of thinking of products and movies as both things which have unique and compartmentalizable "features" (which lead to the notion of MVP) is a flawed analogy for this reason.
I think that we agree the process of MAKING movies is OK, but the process of distribution and consumption is what needs the change.
I would think a minimal-viable Star Wars would be something like a comic book - that seems to be the path taken by many fantasy/SF/"necessarily set/prop/effects-heavy" films recently.
Before some productions start the studio will put together what's called an animatic (http://en.wikipedia.org/wiki/Storyboard#Animatics), where the storyboard frames are cut together with rough dialog to give an idea of the final product. It's similar to what you're suggesting -- a comic book that moves and talks. It's essentially a film's MVP.
Unlike a comic book an animatic isn't actually a product with end-customers, though, and I thought getting end-customers quickly was the most important part of the MVP doctrine.
I guess that depends a bit of your view of the market. If you think the "customers" are the "bums on seats in cinemas", then perhaps it's not a product. If you're thinking more B2B and view the movie distributors as the "customers" perhaps it is.
Not totally apropos, but calling Primer "minimally viable" does it a bit of a disservice. The low-budget aesthetic feels perfect, and it's executed flawlessly-- one of my favorite films, full stop.
They're fantastic! I'm definitely not trying to say that low budget cinema can't be amazing. In some ways, low-budget indie films more consistently amazing than the blockbusters. But are they MVPs?
http://en.wikipedia.org/wiki/Primer_%28film%29 ($7K)
Another one would be 'The man from Earth'
http://en.wikipedia.org/wiki/The_Man_from_Earth ($200K)
Both are (I believe) awesome movies, especially taken into account the very limited budgets.