I don't buy current sets and keep them sealed, but I'll share an fun accident related to this.
The other day, brickset had photos of a set that I had completely forgotten about. It was the police headquarters, 370-1 from the mid-late 70s. I had that set and knew I still had my original legos in the basement. I was fortunate enough to find what I think is probably 90% of the original set I had way back when, including the baseplate. I also found some of the older style legos that were from my older brother (plastic-y colors, bottoms are different, lego people are huge with big round heads. Also found an idea book from the mid-80s with some of the stickers left. I remember totally being into Lego, but they really cool space sets and castle sets were just too expensive to justify at the time.
Anyway, this big bag of legos from the 70s and 80s, I find this:
I know it's not really worth anything $$-wise, and it's kind of cool to have it after all these years. Turns out up until a few years ago, it was stuck in my mom's desk with a bunch of old school photos, papers, etc...it had just never been given to me for whatever reason.
Anyway: the dilemma of it is, open or leave sealed????
-John