Bava Batra 105: The Last Statement; Keeping Status Quo; Disadvantaging the Buyer

Through a number of case examples, the rabbis reestablish a number of principles through their conversation in today's daf.

First, they walk through the addition of a month in the course of a year.  If one is to pay a certain amount of money per month, or 12 per year, what is done if a 13th month is added to the year?  The rabbis look at the contract.  However, they assert that the last agreement is the one that will hold.  This principal of leaving arrangements as they are puts the onus on the buyer to make changes through the court.

The Gemara is concerned with whether or not we should follow the last statement in contrast with whether or not we should follow the agreement that is least advantageous to the buyer.  The example of a landlord collecting his tenant's rent in the middle of the month is used to illustrate this question.  It is clear that in some cases, the buyer is more disadvantaged and in others the buyer is less disadvantaged.  The rabbis watch these arguments bump up against each other.