The Price of a Curse

His hand slides over the edge of the table, he examined the gallery of historical items, grooming his grizzly mustache. He stopped on an arrow, a thick shaft of dark wood, fletchings of rainbow feathers and a head of true obsidian glass.
He carefully picked it up and examined it, engraved on the shaft a line in a long lost language, intrigued, he turns the arrow towards the Iranian shop owner behind the counter and shouts "How much!?"
"Ah! The Cursed Arrow from Africa! It goes for $50!!" He responded.
"$50!? For a CURSE!? No one would pay more than $30!"
"It's an unreplicable piece! I shouldn't be selling for less than $100! $50 is a bargain!!"
"Bargain!? To curse myself!?"
"That's the thing! It doesn't curse you! Anyone pierced by the arrow isn't killed, but has to follow any wish you make!"
The man grooms his mustache again, pondering. Then, he stabs the shop owner in the hearth! "Gah!" The owner shouts. The arrow went through his robes without piercing, went into his chest without drawing blood, the old man grins.
"I wish… to buy this whole shop, for this penny." The old man says with a self-satisfied grin, pulling the coin out of his pocket.
The shop owner narrows his eyes "You son of a gun…"
After that day, the Iranian never again told what his items did before selling them.