I like to buy sealed toys so I know they're new. Any flaws are production errors or my fault, not someone else's. Then I throw out the boxes - it's not worth wasting my space with boxes just in case I resell them. I keep G1 and G2 packaging - anything newer is just landfill and recycling. If I had a choice between a loose mint toy with stickers unapplied then I'd prefer that than a second-hand one with all its packaging.