I am not sure as to why some of you are so negative about selling or buying a box. When I buy a knife and it does not have a box I take that into account when I make the offer. It makes selling the knife easier and also helps when buying a knife.
Expensive items hold their value better, I'll give you some examples, a box for a Rolex President goes for $400 and does add value to the watch, Blue boxes from Tiffany's add cache to a gift and are bought and sold everyday. Antique toys are worth much more if they have the original box etc. Boxes from expensive or antique items are more easily sold and boxes from these items have their own value.
I know that I am more comfortable when an item has a box. I have bought boxes in the past for knives that I own and even one sent to me from Italy (Lionsteel) . If I have forgotten to list it as with
" box and papers included" most buyers will ask specifically if I have the box and papers, I do the same. On the occasion that I buy a knife without a box I always try to hunt down the box for it.
The nasty comments made about the people buying or selling a box are inappropriate. As the OP wrote the listing said BOX ONLY. The people selling the boxes are doing a service for the people that need them.