The following are the vendors I found to be the best in dispensing quantities of a gram or greater of alprazolam powder from the United States. If you feel I've omitted anyone or know of a vendor who does custom listings, please let me know. Prices are rounded and include shipping.
Agora:
Silk Road:
Evolution:
Powder is the most efficient means of obtaining substantial quantities of Xanax at the most cost effective price. All alternative forms; bars, liquid, and blotters, can be produced most easily and directly from powder as well. Hopefully this helps someone out in their search.
Thanks!