You only make money if it sells. Farming up "55 frost lotus, 80 stacks of herbs (lichbloom, icethorn), 34 eternal life" is not the same as making a couple of gems, that's a lot more product to move against other people also farming the same things. And that gold per hour drops drastically once you start flooding the market against professional farmers, who will be more than happy to get into undercutting wars with you. And the more you do it, the faster the market becomes over-saturated and sales drop to a trickle because people just don't need any more after stocking up on deeply undercut herbs. Especially once people aren't overloading themselves on flasks and pots to tackle the learning curve for The Lich King raid.

You say the Lotus sold, what about the 80 stacks of herbs and 28 Life? Because if those haven't sold, it's only a profit of 660g per hour, assuming he sold them at the 60g per average.