Is this an OK thing to do. I'll admit that I've run lowbies through instances before, but never for gold -- usually it's a friend of mine who just wants some extra gear from a certain instance. And I've been offered gold for an instance run, but I've never accepted it, and I'm not even sure what I would charge to actually run someone through an instance (I'd probably have pretty high terms: 5-10g and a portion of the drops, depending on what class was going through).
Have you? Do you think this is the kind of thing that's legit (and if so, should Blizzard maybe even implement a "looking for mercenaries" channel for lowbies to find their benefactors?), or should lowbies all go find their own groups like you had to and stop pestering you to run them through Wailing Caverns for their pittance?