If I am trying a new product/color of any brand I hold onto packaging at least a week or so. This is to make sure if I have any kind of reaction or do not like the product I can return/exchange it. If is is a dup or product I use regularly I pitch/recycle it. MAC LE, I hold onto my boxes, folded flat in an organizer drawer. Not so much with selling in mind, but often it is because it is unique & cool. It could be that whole unboxing thing...sometimes the packaging is more fun & exciting than the actual thing inside. *chuckle*