Ves, you have a large collection of Aus posters. The connection / attraction is not reliant on you physically being at the original theatre release, is it? You are a collector, that's who will buy the posters. More collectors entering the field.
Yes I agree, my attraction to the posters is not reliant on being at the screening, but it is pretty reliant on actually being interested in all types of films. I don't like horror, so I don't collect it. I don't like Sci Fi so I don't collect it. I lurve Vincent Price, so I collect Vincent Price...I'm an aussie so it is interesting to me to see how our films are "sold" overseas as well as at home...
I just think that the generational collectors to come to this hobby in the future having limited or no exposure to say, silent films will be less likely to pay the big bucks you think they are going to command, and will generally be interested in what they grew up with, and happier to spend their big bucks there.
I'm not denying there will be the odd collector here or there, or the odd purchase by a non collector to have the nice old poster on their wall...I just don't think that there will be this mass migration of new collectors to the older stuff...