Membership on the MPF has nothing to do with your social or financial status, it has to do with what you can contribute to the community (i.e., original screen used props).
From your post here, it sounds like if you were able to join you sole post would have consisted of asking to either purchase (if you could afford to) original pieces of your costume, or asking for pictures/information to make replicas (which is strictly forbidden on the MPF, there is _NO_ replica talk there. To use the Fight Club rules analogy, the first two rules of MPF are actually 'You don't discuss replicas on the MPF.' If you want to talk replicas, you come here.)
So, be honest, you've been a member here for nearly a year and have made 18 posts (all of which seem to be related to trying to make replicas of missing parts of your costume, and one complaining about not being granted access to a website), how much would you actually be contributing to MPF?
And it's not like you have to have some insider/useful information or anything, everyone has to start somewhere, but if you came off just sounding like you wanted information to make replicas then I can guarantee that's why you weren't invited in. If that's all you want, then just post about it here. A great deal of the members of the MPF are members here, they'll see it. If they have information to provide (and want or _can_ offer it), they will. If they knew where additional screen-used items are (and think the owners might help), they'll forward the information along. But there are some people that just aren't interested in helping people make replicas for whatever reason, so there may not be anything anyone can do to help.
As for advertising, where do you see the MPF _advertised_? (Not saying it's not, but I've never seen any, but I use adblockers anyway...) And where, other than the WWW, would you suggest they put it? It's a website that you have to be a member to view, I can list hundreds of those... The studios themselves have some really impressive photo archives _on the world-wide-web_ that I bet every member here would kill to get access to (you'd probably be interested in 20th Century Fox's archive site). I could even post the website URLs. But that wouldn't do you any good since you don't have access to them (neither do I, so no need to ask.
) The world-wide-wed IS where you put sites that you want others to have easy access to. If you don't want everyone to have access, you make them sign up in some way.