That's not true. If I receive artwork, a car, shares of stock, room and board, free tuition, etc., then that is income on I which I will owe taxes. Figuring out the value of these things isn't a guess. It's an estimate based on actual market data. It's actually kind of easy in the case of a rental property since the landlord will have advertised the rent amount. So, if he wants to pay lower tax then he can just lower his ask.