Anon,
I think if more people were forthcoming about “not doing something the community does” (albeit one that is not halachically related), the more people would feel comfortable also bucking the trend. I think we would all be surprised how little money other people have (it seems like everyone has so many extra resources except your own pocket book…) – why rely on takanos to stand up for yourself? They take the pressure off of those who cannot afford it and shouldnt be spending it to begin with.
If your kids are not responsible enough to understand basic money principles, how can they get married???? You are sending them into one of the biggest responsibilities in their lives, which will bring many challenges and frustrations, but you dont think they can handle the word NO? Should those kids really be getting married?
