Re: Besides, who are you that you should be setting a price upon your friendship?
Not quite; rather, that "such that" is a reasonable explanatory paraphrase (though "that" is a conjunction, in the structure itself):
Originally Posted by AlJapone
1. Who are you, that you set a price on your friendship?
2. Who is Silvia? What is she, / That all our swains commend her?
If we call the interrogative clause X, in this structure, and the that-clause Y, we can say that Y presents some notion or fact which justifies the asking of the (rhetorical) question in X.
Thus the "setting a price" justifies the scornful "Who are you?" ("Who do you think you are?") in #1; while the swains' commendations justify the admiring "What is she?" ("What kind of creature is she?") of #2.
Not a professional ESL teacher.