You don't need recipe scrolls for the Darkwood armour set. As far as how much a set goes for, it's been a while since I saw a set on sale, but you could shop around and see how much the items to make the set would cost. You will need 20 each of the minor ingredents (Blight, Taint, Corruption, Muclent, Putrefaction, and Scourge), 1 each of the peerless main ingredent (Prox. Lard, Dreadhorns mane, Grizzled Bones, Diseased Bark, Eye of Travesty, Captured Essance), and finally the right lumber combination so that it comes out all 70's.