Lovely Black Dress is a cloth chestpiece. It has no level requirement and is neither bind on equip nor bind on pickup, thus can be sold, traded and/or auctioned. As it is required for a holiday achievement, it is often more highly valued at auction than similar dresses.
Receiving a Lovely Black Dress from a Lovely Dress Box is required for . (That achievement is NOT part of meta-achievement.) Note that receiving one from another player or through the mail does not satisfy the condition for the achievement.