I've had some other idea in mind: an NPC who could attempt to upgrade your crafted items so they could get better stats. He would require a crafted item (with buffs) and some cash. There would be a chance to have stats increased or item upgraded, but there would be also a chance that the item gets destroyed and no refund.
How about it?
Btw I don't like the idea of getting unique items (like Pulse Rifle, Gauss Rifle, Power Armor or Vindicator) via exchange of items that can be farmed/mass crafted.
Exchanging dog tags for EA/BoS helmets/armors doesn't seem bad though.