Just northwest of fizzlecrank is a cave i've been farming for 2 days with great results for minimal effort.
head to the bottom of this cave and look for the offspring of magmothregar in a little alcove at the bottom of the cave. the offspring have around 2k hitpoints and a fast repop. on my mage i simply aoe big groups down and wait 30-45 secs for a repop.
after 20-30 minutes i usually walk off with 4-6 stacks of frostweave, 3-4 greens, plenty of vendor trash. they drop 13-14s per as well.
i have 200-300 gold per hour and on my server, stacks of frostweave are selling for around 80g.