Just figure out which ingredients you want ... most ingredients you can order from Mountainroseherbs.com for about $8 - $9 per lb (and you can order them in 1/4 lb increments).
I usually use wheat grass, barley grass, oat grass, lemon grass, shave grass, afalfa, spinach powder. All organic.
It is hard to find Kamut grass powder though, and I think that the stuff from Alkalive is probably more potent because it is juice powder, not just grass.