gavra_at_work,
the only way to stop it (unless you have another idea) is to stop funding it, and use the money to support local Yeshivos (which is the Halacha in any case).
No, I don’t think a Chinese style cultural revolution against lavish weddings would be very productive at anything except marginalizing an already vulnerable segment of our communities.
I do have other ideas:
1. Education – teach children the value of homemade goods, quality over quantity, counting blessings, and even modest weddings. That way, when they are getting married, they will desire and appreciate a modest wedding.
2. Go out of your way at a modest wedding to tell the bride and groom and the families how much you enjoyed yourself, and how beautiful everything was. Be earnest and honest.
3. Speak to your rabbi about the issue, maybe he’ll do or say something about it.
4. Speak to your friends about the issue. The more people hear it, the more “normal” it becomes.
5. If you have the merit of making a wedding, make it modest and be very open and proud about it. Even if you could afford something bigger.