I don't know, I have seen some insane prices for sealed Final Fantasy.  I'm talking near $500.
that's just crazy. I have no interest in sealed games. I enjoy this collection because I can play every game in it if I want to. I prefer to have the box and manuals if possible but I'm not keeping anything sealed. especially if it's a game I don't have.
I've got a lot of action figures and Hot Wheels so I get the Mint in Box thing I'm just not following that philosophy in my game collection.