Ketubot 99: Buyers & Sellers; Responsibilities & Ramifications

We have learned that an agent is held only partially responsible for an erroneous sale.  The seller is also partially responsible.  Today's daf begins with an elaboration of that principle.  Is the agent always responsible?  What about grey areas, like when an agent is asked to buy a robe with a certain amount of money but he buys the wrong robe; he spends too much or too little?  Is this the same as when an agent is told to buy an etrog but he buys an etrog and a pomegranate?  What if the money  was consecrated?  The Gemara discusses one who buys legumes in bulk instead of in small quantities.  And if an agent sells to one person instead of two, or vice versa. How might each of these circumstances cause problems? Who is held responsible?

A new Mishna tells us that a sale of property is void if it is one sixth more or less than the adjudicated value of the property.  The Gemara begins to understand the implications of this statement.  Do women benefit from such rulings?  Or are they intended for other business purposes that do not generally directly involve women as primary actors?

Contract law relies on knowledge of other contract law.  We cannot understand the ketuba - its structure, its applications, its limitations - without understanding related contracts of the same era.  Still, the arguments relating to ketubot often verge on what seems petty.  If a person spends one dinar more there is a legal consequence; a buyer and a seller take on very specifically stated roles and responsibilities.  The ramifications of these little details are of great interest to me.  What this tells us about how people were able to gain respect, for example, or access the legal system.  But the details themselves are quite tedious for me, even when they involve "buying robes", which teaches us about the garments that people wore in the times of the Talmud.