If you only collect post 1980 posters, you should only collect them mint and rolled. 1980 to 1985 would then become your own personal challenge since a lot of posters were still sent folded pre 1985, but it's a fun challenge. If you collect pre 1980 gear, then you don't have much of a choice, unfortunately. Sure, some could pop up, like Jaws, but they are an anomaly. I think Ed only collects rolled posters. I could never do that, because there are way too many posters I want.
T