> Caviar was served as a free bar snack, in the hope that as with peanuts, the saltiness would encourage drinking.

So it isn't just the cheap stuff.

I do have a note about the source, though:

> Salt: A World History by Mark Kurlansky

This book vectors the myth that Romans were paid in salt.

This is not true:

http://kiwihellenist.blogspot.com/2017/01/salt-and-salary.ht...

(Wikipedia has, of course, been fixed. The printed material never will be.)