The roman monetary system is still in place in towns and cities. In rural areas bartering is more common.

              Solidus (coin)  Argenteus Nummus Radiate Laureate  Denarius
Solidus         1       10 40 200 500   1,000
Argentus 1/10       1         4 20 50   100
Nummus         1/40       1/4 1 5 121⁄2   25
Radiate         1/200       1/20 1/5 1 21⁄2   5
Laureate 1/500       1/50 2/25 2/5 1   2
Denarius 1/1,000       1/100 1/25 1/5 1/2   1