I've got an awesome deal going on right now. One guy is a pretty regular herb farmer. He mails me stacks of Frost Lotus for 300g COD a stack, Goldclover and Lichbloom for 7g COD a stack. A second guy takes as much Frost Lotus (350g a stack), Goldclover and Lichbloom (20g a stack) as I can mail him.

I basically log on, empty mailbox, COD it all to the 2nd guy and reap the rewards. It's the easiest gold I've ever made and I make probably close to 4k a week off these two guys.