At the Greek seafood temple Milos in midtown Manhattan, fish are shipped in from the Mediterranean and priced by weight—some upward of $50 per pound. But the salt is equally valuable. Owner Costas Spiliadis buys Greek fleur de sel from Kythira, a pristine island where lots for harvesting sea salt are auctioned off to residents. Spiliadis uses the hand-gathered salt at his six Milos locations around the world. “I don’t think it would be fair to say, because of the sea salt, my prices are higher by that much,” says Spiliadis. But since his salt costs 10 to 15 times as much as other gourmet salts, per Spiliadis’s approximation, the price does add up: Greek salad, seasoned with the salt, costs $33. And the salt-crusted fish has a $15 supplemental fee attached.