aries: Perhaps your aren’t familir with the typical style of how shadchanim operate. You may be uncomfortable with it, but the vast vast majority of shadchanim including the most prolific in the country have never told anyone any rate for a completed shidduch. People give them what they want.
That doesn’t change the halachic obligation for the parties to compensate the shadchan according to community norms. Perhaps you would like to instite a societal change whereby shadchanim stated up front what thier rates were, hwoever the present situation being what it is, the parties are obligated to compensate them accordingly. Furthermore, unless there is a structure, whereby non proffesional shadchanim get compensated different than proffesional shadchanim, the requirement would be to compensate non prossionals the same as proffesonals.
As for you comment re: the shadhan “must get paid before the chuppah”. I don’t believe that to be halachically correct. When one needs to pay the shadchan is at the time shadchanus is due-no a day earlier, and one shouldn’t pay a day later- when that date is will also depend on community norms. Some place the stlye is to pay after engagement and some places the stle is to pay after the wedding. Under the present system for shadchanus, the halachos of compensating shadchanim are part and parcel for the halachos of paying “kablonim” – workers who get paid for completing a job- and thus follow those guidlines.
Dash: To the best of my knowledge, (although i fully agree that the more difficult a shidduch or the older the parites in question, the more one should compensate the shadhcan) being that that is not stadard practice – and compnesation for workers commisioned or otherwise where no price has been set in advance is governed by societal norms – thus halacha doesn’t require it.