I saw Primer at a theatre in SF, that 7K figure is just marketing/publicity for the movie.
First of all, you've got the DP saying he shot in mostly available light. That's going to give you some grain, no doubt about it.
There is lots of grain, so much on some shots it becomes a slightly surreal reality -which works for this movie. For a drama, it might not work.
Anyway, it seemed to me he (director) "made" a film out of 1/2 a narrative and a lot of other footage tied together with voiceover - maybe that's why it took him 2 years to edit.
Anyway, lots of grain throughout, but enough "wtf is going on?" to keep you interested, and now the guy is getting every script in Hollywood thrown at him. So there you go. :rolleyes: