The dominant coin of both the Republic and the Empire was the silver Denarius, which weighed 4 oz. When the Denarius was first struck in 211 B.C., its value was,
1 ox = 10 sheep = 60 Denarius.
Roman soldiers were paid 120 Denarii per year until 50 B.C., when their pay was doubled by Julius Caesar. Some additional examples:
A cavalry horse cost 312 Denarii
A slave cost 300 Denarii
A tunic, toga, and sandals could be purchased for less than 100 Denarii.
The Denarius lasted 450 years as the most common Roman coin (211 B.C. – 243 AD).