Kiddushin 7b: Evaluating the Kiddushin Object and the Issue of Semichas Da'as

This shiur analyzes a fundamental machlokes in Kiddushin 7b regarding whether an appraisal (shuma) is required when a man is mekadesh a woman with an object whose value he specifies. The Gemara (גמרא) presents a case where a man was mekadesh with shiroy (silk garments), and Rav holds lo tzrich shuma (no appraisal needed beforehand), while Rav Yosef requires shuma. Rabbi Zweig begins by identifying a difficulty in Rashi (רש"י)'s reading: when Rav Yosef says "tzrich shuma," Rashi interprets this not as a procedural requirement to perform an appraisal, but as a legal principle stating that since shuma is necessary and was not done, the kiddushin is invalid (ein ha'mekudeshes). This is a departure from the straightforward reading where "tzrich shuma" would mean "go ahead and make a shuma." The shiur raises four fundamental questions on the Gemara and Rashi's interpretation. First, the Gemara discusses a case where the man says "kol dahu"—meaning "whatever it's worth"—and states that everyone agrees no shuma is needed. Why does the Gemara need to mention this obvious case? If he explicitly says the value doesn't matter, what possible requirement for shuma could there be? Second, the Gemara says that if he states "fifty" and it's not worth fifty, she's not mekudeshes. Again, this seems obvious—why state it? Third, what is the nature of the "chasar semichas da'as" (lack of reliance) that Rav Yosef sees in the case where he says fifty? If she's willing to be mekudeshes for fifty and will only be married if it's actually worth fifty, where is the problem of semichas da'as? She gets exactly what she bargained for or she's not married. Fourth, how does the Gemara's language fit together—particularly the relationship between saying "kol dahu" and specifying an amount?