So, the other day I thought I smelled smoke somewhere, and my house was on fire. There happened to be some of Crassus’ slaves around and they refused to put out the fire until I sold my house to him for a ridiculously low price. My atrium is ruined and now he’s charging us an unbelievable amount of rent.
You might consider having his firstborn framed for poisoning a noble. If he has no one to pass his own home to under threat of discovery, he may be more willing to discuss equitable terms for rent.