At this point I've summoned for about 10 or so Warlocks. I'm not tired of this at all and happily await more business. I advertise in world regularly. Some have asked if I'll take less if they summon me to a cleared ID, and the answer is yes.
50g: I'll do a full run with you and summon the demon event when we get to it. Most take this option because it's easy to do with pugs.
25g: I'll come to your cleared ID(ideally with a summon to the door) and summon the demon event. It should have all pylons down. I don't mind fighting Immol or Prince, but I will still greed roll drops. Only 2 Warlocks have done this so far, since it requires cooperation from other players.
One run I did had 2 Warlocks doubling up, splitting the cost so they both get the event in 1 run. This is clever as I do not charge per Warlock, but rather per run. This is possible because there are 3 dps slots in a group and everyone present gets credit for the quest. If you want to do this, you just need to find a second Warlock that needs the quest.
To contact me, I am usually on Schuss or Untoten, and often post in world. This is Horde side. At the time of this post I'm currently in DMW for another one. This one is for Snupo.