This is a discussion forum, not a wiki. While there is a search function, and it is useful, the very nature of a forum is more discussionary in nature, and not just bulk knowledge storage. Sometimes it's difficult to weed through all the BS to perhaps find the piece of info you're looking for. Also, I'm willing to guess that a lot of the Potter discussion is old. Investment tips from even a year ago might not apply today. The OP had a ligitimate concern, there's new Potter material coming out out, that's a new development and it definitely warrents new discussion on strategies for sealed Potter sets.
Remember, there are people here at all experience levels in lego investing, and with varying degrees of internet savvy. I just got done building the VW camper van, so I'm feeling a bit hippy-ish.... "be cool to each other, man"