Found an elder sword in Bestiary

Does this have decent value? Is it possible to mastercraft a mod on this? I'm thinking this item has at least 1 open prefix/suffix.



Also, I found this helmet. Honestly have no clue what it's worth. Good life, and rarity. And I think it's got an open slot.



Worth using an orb of annulment on either of these items? I'm thinking the helmet is a better candidate.