I ended up actually going with Vibrant Health XP Chlorella from mercola.com. My doctor told me to go by his recommendations for how the dosage, and I was limited on time, so I caved and just bought his brand because I wouldn't have to calculate any differences in dosage or anything that way. But there are definitely comparable brands. If you read the standards they use (click on the links above), do a search for yaeyama chlorella elsewhere, and compare the two, you might find some for cheaper. But if you don't want to go through the hassle, mercola.com does have a high-quality one. And in capsule form, it's not much more than other brands. If you are gutsy enough to go with the powdered form, you can save a lot of money (but it does taste algae-like).

~Tia