The "elite student in music room 2" turns out to be Haruki's delinquent classmate, Kazusa Touma.  With his characteristic pushiness, he tries to get her to join the light music club.  But his pushiness backfires, and only makes her more annoyed.  Setsuna gets irritated... no, involved, and approaches Kazusa secretly.
Oh, don't worry about the money.
Oh, mach dir um den Preis keine Gedanken.
Ah, no te preocupes por lo que costó.
Ah, no te preocupes por el dinero.
Ne vous inquiétez pas 
pour les frais,
Ah, não se preocupe muito com o preço.