Currently the cost of the salt (for human consumption) is practically negligible, mostly around $1/kg.
But it wasn't always so. There were centuries as salt mining and selling was a governmental monopoly, and the government used it as some type of a "luxury tax" - similarly, as we can today see in the case of the benzine in some countries. This made salt prices irrationally high.
But making kosher meat requires a lot of salt.
What should be done, if a kg of salt would cost a hundred dollars?