Magister Errickin:
How much are you willing to pay?
Hmm, you must be here on the orders of another...
No matter. In order to obtain Stabilized Ectoplasm, I first require plain ectoplasm, which is itself a rare item.
In fact, I have need of it as well...
You have the look of an adventurer, so I will strike a bargain with you.
Exterminate the Mirror Ghost and the Mummy in the Forest of Mirrors and you will be able to acquire ectoplasms.
Thirty ectoplasms will produce one Stabilized Ectoplasm. Bring back 35 of them and give me 5. Then I will make you a Stabilized Ectoplasm using the remainder.