For a while after I first started last year, a couple friends and I would go to the Fel champ spawns for power scrolls. Even though we got raided, a lot, and even though we lost the spawn in almost every raid, we still came out so far ahead, gold wise, to make it worth our time.
We stopped for a couple of reasons. First, the more difficult champions made it easier for the raiding guilds to find us and do something about it in time. And second, we (all three of the guild's "regulars") got involved with other things in real life.
So now if I need more power scrolls, I'll buy them. And if I need gold, I'll do peerless or Doom.