Perhaps for AP's and Necro's, who tend to be heavily hunted, it might be a good idea to have evil mage mobs that can give hints.

Make these mobs summonable and possibly for high enough level characters make it so that some form of demand can work. Instead of bribing them they bully the info out of them. I could see that is legit evil mage RP to use fear as motivation to get what they want. This of course wouldn't work on guildmasters.