I doubt there is a correlation. Sounds like something people say to influence a couple not to spend a lot on a wedding, or to not feel badly that they didn’t have a lot to spend on a wedding. Kind of like it’s food luck if it rains on your wedding day. Make the bride feel a little better her outdoor wedding got screwed up, or that people had to come out for a party in the rain.
I don’t know how expensive is expensive?
Traditionally, the parents are paying for the wedding, so it seems like it wouldn’t have anything to do with the couples happiness. I have a cousin who had a really nice wedding, and they’ve been married over 30 years. I think the most expensive wedding I went to she left him on the wedding night. Went down to her parents room at the hotel and never went back. They had already been living together 6 months. Maybe if it had not been such an expensive event she would have cancelled it before, I don’t know. Everything was in motion. The second most expensive they have been together for 30 years. They were probably $50k and $30k respectively.
A woman I worked with told her daughter a few days before the wedding not to worry about the deposits already spent, if she wanted to cancel the marriage it was fine with them (both parents of the bride). I don’t think it was wildly expensive, but I’m sure it must have been several thousand. They divorced after a few years.