Rabbi Dr. Wikler (p. 142) quotes a story of a Chassidic Rebbe looking for a shidduch for his daughter who would pay shadchanim for proposing a potential match even though the Rebbe declined the offer. He would say, "Just as we believe every match is decided in Heaven, we also believe that it is predetermined just how many proposals we must listen to until we hear the right one. You sugestion brought us one closer. For that you are entitled to shadchanus gelt."
Is there a source for such a concept of a predestined number of proposed shidduchim?