When you left the roman army how much money did you get

Up to 107 BC you got none. Having completed the campaign you were called up for, you went home to your farm. It might have had a successful conclusion, and you might get a share of the loot in that case. The Roman army at that time was a citizen militia.

After 107 BC, with the Marian reforms, soldiers were recruited from the landless class and the army was made professional. The career lasted at first 16 years. It was then increased to 20 years. On discharge soldiers were given a honesta missio, a plot of land to farm (agraria missio) or a sizable lump sum (nummaria missio), 3,000 denarii under Augustus; Caracalla increased it to 5,000 denarii. Soldiers who were discharged prematurely because of illness or wound also received these benefits (causaria missio) and so did soldiers who were discharged by their commanders (gratiosa missio). Soldiers who were discharged dishonourably (ignominiosa missio) did not receive anything. Auxiliaries (non-Roman allied soldiers who served in auxiliary troops which supported the Roman legions made of Roman citizen and whose service was 25 years) received Roman citizenship and the right to marry a Roman woman (Ius connubii) in addition to the agrarian mission or the numnaria mission.

The hosesta missio was a document which legally sanctioned the end of military service and certified that the service had been carried out honourably. It was given to both legionaries and auxiliaries.