Personally I farm WotLK ore seeing as it goes for a handful on the Auction House, cobalt & saronite are required for JC/BS/Eng you cant skip them and stacks of bars go for about 180g on my realm. I pull 7k easily while I am sleeping with all auctions selling the next day. I'll change up with GIO/EBC & pull the same.. with only one bot.
What do you do?