This might be a repost, but couldn't find anything when I searched.
Anyway..
Story time: Once upon a time, I use the [Archmage Vargoth's Staff] for my [/use Archmage Vargoth's Staff /vanish] macro. Ohhhh sweet jesus how I loved that macro, but god damn i hated to keep that quest in my quest log. Then i leveled my mage and got to the quest chain and found away around it
I noticed that [Archmage Vargoth's Staff] is obtainable if you delete it.
You'll need: Carbonite or another quest helper addon that has the right-click abandon function. Example Attachment 5057
What to do:
1. Go to Ravandwyr Ravandwyr - NPC - World of Warcraft
2. Delete your [Archmage Vargoth's Staff].
3. Then talk with him and keep the window open. You should see the option "I've lost Archmage Vargoth's Staff. Can you replace it?"
4. Now right-click on your quest ( in my case "The Sigil of Krasus") and press abandon and make sure you don't close the window.
5. Now when you have abandoned the quest, press at the "I've lost Archmage Vargoth's Staff. Can you replace it?" option, and you will obtain the Archmage Vargoth's Staff but not
the quest.
I think this would work with any other "obtain when lost"quest items
Btw sorry about my bad English Hope it's readable