Bava Metzia 50: How to Deal With an Ona'a

We have been discussing the Torah prohibition called ona'a, where a person uses his or her power to gain advantage over another person in business transactions.  This could be done through overcharging or undercharging, depending on the situation.  Steinsaltz teaches that there are three levels of ona'a:

     1) when the amount that has been overcharged needs to be returned
     2) when the ona'a is so small that we assume that the parties do not care about it; 
         it is not returned
     3) when the one'a is so large that the transaction itself is nullified

Reviewing our dapim from the past three days, we are reminded that the standard amount over or undercharging called an ona'a is one sixth of the value of the transaction.  According to the information above, exactly one-sixth of over or undercharging must be returned.  More than one-sixth of the transaction nullifies that transaction.  And an ona'a that is less than one-sixth of the transaction does not need to be returned.  

Most of today's daf addresses examples that clarify the time limit on asking for the return of an ona'a. Generally speaking, our Mishna teaches, one is permitted time enough to show the bought item to a friend or relative.  Anything longer than that amount of time suggests that the price has been accepted and that there will be no later claim.

But how long does it take to check with others?  Which others, in particular?  And is a day measured as twenty-four hours?  The rabbis are concerned about these details that might create uncertainties regarding serious claims of misrepresentation or abuse of power.

The Gemara also speaks to the rabbis' concerns about whether or not an ona'a that is less than one-sixth is addressed in any way.