I am a sealed collector as well..i don't do it with the mindset that I will sell and make money down the road..i do it, because I enjoy the feeling of it being "brand new" each time I look at it..i just like that "fresh from the store" feeling
..if there is such a thing..i also don't like how sometimes if you open the package..the seal permanently damages the box, leaving sticker residue or small tear marks to the flaps etc...again, collecting especially the international editions are expensive, so I like to keep things mint as possible..and for me..it means sealed.