Scipio sowing Carthage with salt

[Nihonius Legio]

I just dont see why it would be worth so much to a culture so near the sea. The majority of land owned by the Roman Empire was near the coasts, and most of it's largest cities were sea-side as well. I could understand people in central Germania putting a high price on salt, but people in Italy? Just go drink the ocean, there's plenty to go around.