Speaking and agarwood, which is a staple of Buddhist incense, I should mention that the stuff is, uh, endangered, according to the Convention on International Trade in Endangered Species (CITES). So that's kind of a quandary for those of us (and yeah, I count myself among them) that don't want to destroy the earth too much.
However, unlike certain things, it appears that the folks doing this convention have agreed to, er, study the problem.
It is known- you can google it yourself - that Vietnam is attempting to create sustainable "farm-raised" agarwood. (You don't just raise the trees, you see; the stuff has to rot for a while, and not just any rot, of course, but a special rot which gives agarwood its unique properties).
Anyway, if you do buy the stuff (and I do), treat it with care and do not waste it, and appreciate it. It seems a ridiculous expenditure in these times perhaps (although I can't countenance purchasing the really high end stuff) but on the other hand, there is nothing that conveys what agarwood conveys for zazen and chanting. Yeah, yeah, there is great misery and want in the world, but a zendo is not a space of denial and asceticism, nor is it a place of ridiculous indulgence.
And if there's a way to help foster sustainable methods for producing this stuff, let me know. I can't believe there won't be alternatives found for exterminating the agarwood species; I just hope the folks who are dead set against genetic engineering can deal with it.