I'd be considered new to this hobby I guess, and I've started collecting the boxes off of the gear I've been buying for resale at some point. And I do get that, and think it's a viable excuse to hang onto them. Although a Monitor 75t box fell on me in my work room one day (just scared the hell out of me) and it discovered the sharp end of a box knife As you can see in the picture, I don't have much at this point but it IS taking shelf space away from my daughter come Christmas and she needs a place to stash the grandkid's loot before the big day. BTW, I know it's great for resale to have the original box, but I sold the Yamaha in the pic today, and was quite proud when the guy came over and I opened it to remove each piece. I even had the little plastic bag for the remote. Then he said "I don't want the box, you got a bag I can put this stuff in?" *sigh*
Anyway, I'm just an amateur. I'd love to see some of the box collections you long timers have, so please post a photo! Oh, and try to answer the question...at what point is it hoarding??