When I was doing Alchemy from 300 to 350, Vox's Dust was the only herb missing from the inventory of Alchemist Redsa in PoK who is the all-in-one alchemy vendor. Assuming that's an oversight, could we please add this item to her wares?
If it helps tracking it down, there are some merchants in Crescent Reach who are hoarding Vox's Dust in the alchemy area.