I know some 'collectors' who spend a ton of dough acquiring a rare SEALED LP. They just look at it, coz if they open it, they believe the value of their treasure goes down. Some acquire a second copy (used) to play on their ttable (this still costs some) or a CD copy to preserve the sealed copy. They are so happy looking at the sealed LP and holding it in their hands.
To me, its the music inside the sleeve that matters. I don't see the point of keeping it sealed after spending a ton of dough, and never playing it in your lifetime.
I grew up with LPs. It was always special opening a sealed LP, pulling out crisp sleeves with the fragrance of a 'fresh' LP permeating your nostrils. After gingerly placing the shiny LP on the platter, you carefully cue in the tonearm/cart with your hand (sometimes shaky) and wait in eager anticipation for the first notes to sing...you can't do that with a CD.