Our western culture is so niave to Asian foods and remedies. I am not sure if it is valuable for what you want (because I am ignorant to this), but I think if I were in your shoes, I would do the same, if someone suggested it. It is probably so expensive because it has to be shipped to the US from Asia, and it only grows for one short season. It is in great demand in Asia, I am sure!
Anyway, I hope the videos I gave you help some.