If it's a stick concealer, it should be quite obvious at a glance whether it has been used before or not so I wouldn't have too many qualms about listing them without the packaging. If they're liquid it makes it a bit harder.

If they're actual boxes, not blister packs or anything, I would compromise and remove the concealer, flatten the box, and ship together that way, with a very big, clear note at the top of the listing explaining why. That way anyone wanted to have the box (eg if ingredients, batch number or other important info is on it), will still physically get one.