Searched and found nothing..
So, this is a "common sense imo" thread, but not sure that everyone really have thought about it, so..
If your going Naxx PuG or Guild run for that matter (depends on your morale) remember to look your atlas loot through for BoE epics that are able to drop for the bosses in there ..
Since theres a couple of pretty neat epics in there that goes for quite some gold, for example if your a spellcaster you would like to have Mantle of the Extensive Mind - Item - World of Warcraft (Mantle of the Extensive Mind), and lets say you ALRDY got it, you would like to sell it.. So all you have to do is equipt a blue/downgraded shoulder item before encountering Instructor Razuvious (Instructor Razuvious - NPC - World of Warcraft) who got 10% drop chance on those shoulders, or Gluth (Gluth - NPC - World of Warcraft) 0,5% dropchance.
(And better do it while clearing trash since some ppl may Inspect you just before a boss encounter to see how big a chance they got for winning the actual item). And IF you win the shoulders, just equipt the ones you alrdy had before going into naxx, since they most likely would say something like "Hey, equipt the shoulders you just won, or i report for ninjaing, (insert emo stuff here)."
So basicly at those bosses;
1. Equipt blue/downgrade shoulders
2. Kill boss
3. Win shoulders
4. Equipt old shoulders of same name.
5. Profit!!
(6. Common sense i know, but still read above)
.. This can be done (obviously) for any BoE epic in Naxx , the only thing you have to do is to look through your Atlas loot before going, and get some blue gear for that item that you wanna sell .
I've done this for Mantle of the Extensive Mind (http://www.wowhead.com/?item=39310) 5 times now. And they sell good at AH,
Just remember that you can only do this if you alrdy have the actual item ..
- Hope i made myself clear enough ..
Edit: If your doing this on a guild run, and you dont want your guildies to find out that you ninjaed them by putting the item on AH from your main, its simply just to make an alt and do it from there. I do that with all epics I ninja, just not to get cought.. (: