Not that I'm all that against this (as I love all things Scion), but I don't think there's any real need for this. The extra commerce from haunted lands mechanic is intended to represent the trade generated from the variety of strange objects found and traded there. Adding a unique recource to trade in there would seem a bit of a double benefit. Also, it would seem to apply some consistency in the stuff found in haunted lands (large veins of the same thing to justify a recource), where I was under the impression the things found there were of a great variety. Also, remember the AI difficulties in handling trading for recources...