Under Augustus' time the sestertius was a bronze coin worth roughly four denarii (the silver denomination).

There is an inscription CIL 3, 805,806,808,809 which has a lot of information on fixed prices for wages and food for the third century AD which might give you some idea for how much a normal laborer earned each year: A farm labourer earned 25 denarii per day Sewer cleaner = 25 denarii Carpenter = 50 denarii Baker = 50 denarii Bath attendant = 2 denarii per day

A teacher of Latin and Greek language and literature could earn 200 denarii per student per month

To get a good idea of what you could buy on these wages, a pound of meat such as pork, goat or lamb was 12 denarii, chicken was 60 denarii, beef was 8 denarii, a pint of wine was between 8-30 denarii depending on the quality.