I was thinking of buying a Battle for Zendikar sealed stash and setting it aside for when those packs become really expensive, and then I thought about the Comic Book Crash of 1993. The Wikipedia article on Comic Book collecting needs a lot of work, yet there are other articles on da inter webs on the events of 1993, such as the following article.
I became briefly interested in comic books in 1992-93 and got to live through a speculative boom as a buyer. I still have two boxes of Image comic books from that era in a closet, 22 years later! By the way, that crash took with it many, many comic book stores. If I was running a Local Game Store (LGS) today, I would be diversifying like crazy.
There are many people thinking of a BFZ stash. I even thought of what I wanted for mine: 2 booster boxes of Battle for Zendikar and one of Oath of the Gatewatch (what a clumsy title!), all of the pre-constructed decks, a fat pack/clash pack/event deck of each set, and a solid sample of pre-release product. The total comes to something like $700.
And then I thought about my boxes of now-worthless Image comic books and decided against it!
I hope that if you like BFZ you play the living daylights of it, and if you want to collect it, that you buy a nice supply and enjoy it NOW. As for speculating on it to make some money in the long term future, history is not on your side. I wish you luck! I will not be speculating on this product. I don't want a worthless booster box of BFZ in my closet many years from now, when I have moved on from Magic.