How long to mark a DVD set "missing" until you remove it from the inventory?!
I see that you have 4 copies and think that if I request a copy, it will come rather soon. Except when I look and realize that you really only have one copy, which quadruples my waiting time.
The more to do not act diligent, and subsequently are misleading, the more people will go away! It's all about relationship skill, communication skill.
Bottomline, please purchase more copies of this DVD set to have on-hand. This is a TV show that is still in demand. And arguably will be relevant for many years to come.