Ketubot 100: When the Assessor Errs

The mishnah from 99 - assessments of property made by judges that may or may not be accurate. What happens when their assessment is off, as compared to market value? How do judges compare to the widow here, in terms of assessing the property? Plus, what is the role of a shaliach in this kind of transaction? Also, how these cases compare to other rabbis' handling them in practice. Plus, the mishnah at the end of 100 - a reprisal of Yevamot, with a list of women who don't get a ketubah.