On Interesting Treasure: The Simple Copper Helm
Its age makes it appear to be worthless, and may be discarded by a callous delver. However, any armorsmith will note the repousse from the peak, and the bands around the base.
Extremely observant characters will note that the helm has been damaged and then later repaired.
Scholars will note that this style of helm design is from the legendary Godforge (Goddtaalomar) dwarf clan, said to have descended from Moradin himself.
Sold as a damaged rusted helm: 1 copper piece
Sold as an ancient dwarven helm: 10 gold pieces
Sold as a representation of forging techniques from the Godforge clan: 6,000 gold to an interested smith.
Sold as an ancient dwarven artifact to a dwarven smith after a long discussion about how you are sure you didn't steal it and are just trying to return it to their rightful owners: A favor from the dwarves.