this video from Bellular Gaming and it got me thinking - is that really the most efficient way to make gold in Warlords of Draenor? What they're doing is fairly simple. They're going into Cataclysm raids Bastion of Twilight, Blackwing Descent and Firelands on 25 heroic. Then they vendor everything. It seems like the exact kind of thing that we were doing back before they nerfed raid boss gold for soloing, but it works with the current rules for dungeons in that you basically have to collect every single thing that drops and vendor it. Still, it will net you 4000 gold in around an hour or two, and for every level 100 you have that's another 4000 gold you can farm up. That's not bad at all, really.
I'm not sure it'll remain so lucrative. It does work with the new gold normalization system, which was implemented because you could collect all the trash and vendor it, and it's a series of raids from two expansion ago, so being able to solo them isn't unexpected. For now, if you're gold strapped, keep it in mind.