I think it would really depend. I can imagine cases where a WW bracchus would be worth less than a scroll, as people might value the freedom of applying the scroll to a wolf of their choosing, rather than getting a wolf with colours they potentially don't like. On the other hand, a very low ID WW or a WW with stunning colours that is already turned into a WW and matches your preference might be worth the value of both the WW and the bracchus scroll combined.