It makes no difference whether it was stipulated up front or not. It makes no difference whether the shadan has another source of income or not. It makes no difference whether the shadchan was motivated by mercenary considerations or not. If someone wants to disagree with me based on halachic sources, please do. But this is a halachic issue, and you folks are writing as if it’s about your personal feelings.
Oomis, you wrote so beautifully in the “moral or halacha” thread about how our morals come solely from the Torah. You should know that the Torah has what to say about hilchos shadchanus as well.