The problem you are going to have with storing boxes for any period of time is that all the redeptions that are being issued now compared to even several years ago. Most of the higher value guys are unable to schedule signings in time for a lot of releases. Thus you're going to end up with maybe 10% of your hits not worthless, but not the same and a big hit could be pennies on the dollar. You'd be a lot better off either opening the cards and repackaging them to open later or setting aside a money jar for buying current boxes once he is old enough to join you or buying older boxes cheaper then then what they are originally out because of the possibility of not redeeming cards. I doubt seriously if a child will care if the cards are wrapped in the original wrappers or wrapping paper. Good luck,great idea, my dad only went to buy cards with me once, I remember it well, one rack pack of 83 Topps and pulled a Wade Boggs RC, still have it even though I treated it a little rougher than I should have growing up.