There is such a thing as comparative advantage. The Dog talisman could easily be the most sought after item next round as an example, since it's simple access to a power dream of mankind, but would it be really useful to us compared to the scroll or the cookbook? I don't think so. A similar argument could be made about the Wailing Stone this round even; clearly something that can be valuable to practitioners, but the Stone in our hands would see very little magical exploitation for a while as we simply don't have the magical chops to make good use of it. A item that's valuable in general might be less valuable to us specifically, is what I'm saying, and I think magical knowledge is pretty valuable to us right now, so I want to get as many sources of it as possible.