Salt was expensive.. but in the quantities we shake onto our food today, the price was pretty much negligible. Salt was considered expensive because they used a lot of salt when preserving food.
For reference, US Army regulations during the American Civil War called for soldiers to be given 3 pounds 12 ounces (1.7 kg) of salt every 100 days. Sprinkling a little bit of that onto a meal would not exactly have been opulent. Of course, those ration regulations were aspirational and soldiers were lucky to get what they were owed, but it gives an idea of how much salt people considered reasonable.
For reference, US Army regulations during the American Civil War called for soldiers to be given 3 pounds 12 ounces (1.7 kg) of salt every 100 days. Sprinkling a little bit of that onto a meal would not exactly have been opulent. Of course, those ration regulations were aspirational and soldiers were lucky to get what they were owed, but it gives an idea of how much salt people considered reasonable.