Suet.divus Iulius 50.

When Caesar was selling by auction the property of certain citizens, Servilia, (the mother of Marcus Brutus) bought a valuable estate quite cheaply and so became the victim of a jest of Cicero’s, who said: ” Of course you will the better understand Servilia’s bargain if you realize that a third was knocked off the purchase price of the estate” (tertia deducta).

Note.
Servilia had a daughter, Junia Tertia (the wife of C.Cassius), whose favours- as well as her mother’s - the dictator was then, according to malicious gossip, enjoying.
The play upon the two meanings of deducere –“to deduct” and “to conduct a bride to her husband” can hardly be kept in English.