There's lots of valuable items in the game. Most of the time people don't recognize their true potential and sell them for incredibly low prices. Orb of Deception is one of these.
World drop items - How to obtain?
Orb of Deception is a rare drop from mainly level 50+ chests and a few rare monsters. There is no guarantee you will find one even after a week's farming, but the chances are there. Personally I've found one from a rare monster that I had to kill 15+ times and 2 from treasure chests in level 50+ zones.
You may also find clueless people selling these Orbs for less than 1000g. I highly recommend to resell them for 10x more!
Treasure Chests
You have about a 1% chance to get one from a treasure chest in high level vanilla zones. For more info about treasure hunting, click on the Treasure Hunt category.
Optimal zones:
- Blasted Lands
- Silithus
- Swamp of Sorrows
- Un'goro Crater
- Winterspring
- Burning Steppes
Monsters
- Skarr the Broken in Feralas. 2% chance. 2-3h respawn timer.
- The Razza in Feralas. 2% chance. 2-3h respawn timer.
Many claim they no longer drop it but I can confirm that at least Skarr indeed does drop it. Also his updated loot table is based on his new levels and the Orb has made quite a few appearances. The other old arena rare, Razza, has also dropped it a few times but I haven't seen a drop personally yet. I can't see why they would have a different drop rate so I assume they are 1-2% ish both but the lack of data shows it as a smaller chance. They spawn next to each others so it won't take long to gank them both.
Also the end bosses in old raids (Not that there's many left with all the revamps going on) also have a 100% drop rate for a couple of blues, and Orb might just be one of them. For more info, check the dropped by list.
How valuable is valuable?
It really depends on your realm. If no one else is selling one, you have no limits. Personally I've sold one for 12k, 10k and 5k. Keep in mind though that it's a vanity item and no one "really" needs one.