Pseudoephedrin

i take 240 mg. tablets tll take 120mg. tablets i would try the powder but never have and no one that i ask told me how much of the powder pseudoephederine to take i am looking for a long term  supplier i will order 1 every 3 or 6 months depending on how much your min order  ..but i dont want to order a hole lot ..dont know to much about the laws on how much you can order and dont want to get in trouble.... i have been out for 2 weeks and really need them. let my know the price and mg.thanks