Many months ago, Amazon delivered an extra crate of groceries to me that should have gone to someone else. They didn't want them back, so I kept most of the products. Among them was a grinder of sea salt. Since receiving it I've been using it in place of regular salt, wondering if it was worth the cost premium. For the first time ever a few nights ago, I could actually tell that the green beans I was eating were prepared with sea salt instead of regular salt, due to the coarse texture. And indeed, it was slightly better. I'd be wary of believing anyone who insists they can tell the difference between freshly ground sea salt and regular table salt on anything more complicated than green beans, but I'm willing to concede that there are people in the world far more epicurean than I.
Table salt comes out to about 3.42¢ per ounce. Freshly ground sea salt comes out to $1.3632 per ounce. That works out to a 3882% price premium. My perception of the flavor and texture improvement of sea salt versus regular salt was more like about 5%. I think it might be overpriced.
(This assumes that the destructive pleasure one gains from grinding rocks in a device before eating is roughly cancelled out by the inconvenience of having to grind rocks in a device before eating, which is probably also accurate.)