Salt was very bulky (less so than grain of course) but I don't think it made a very good medium of exchange. Shipping goods on land especially was extremely expensive.
.e.g according to Diocletian's price edict (so the prices themselves are probably not accurate due to inflation by ratios might be) a laborer could afford to buy ~7kg of salt for his daily wage.
Salt was supposedly very cheap, actually the same price as grain by volume. So it really wouldn't have made much sense to drag bags of salts with you just to sell it for pennies (salted meats or fish etc. probably would've have been a much better option).
Hard to say. Money is preferred, but if you find there is no money and you have to go home, any valuable item will do. Salt varied in price as you got away from the southern sunny coastal areas. The edict you cite confirms the coinage problem.
https://en.wikipedia.org/wiki/Edict_on_Maximum_Prices#:~:tex....
.e.g according to Diocletian's price edict (so the prices themselves are probably not accurate due to inflation by ratios might be) a laborer could afford to buy ~7kg of salt for his daily wage.
Salt was supposedly very cheap, actually the same price as grain by volume. So it really wouldn't have made much sense to drag bags of salts with you just to sell it for pennies (salted meats or fish etc. probably would've have been a much better option).