My wife was an only child from a wealthy family; short of destroying the relationship with her mother, we had little say in the cost of the wedding[1]. That being said, it really was a lovely wedding and a good time was had by all.
1: We compromised; the ceremony was all us, her mom planned the reception, with input from us. It is still mind-boggling to me how much her mom was invested; they normally get along fine (both before and since), but I was seriously worried that planning the wedding would destroy their relationship.
Somewhat unexpectedly, [1] which is based on actual university research, reports the opposite: Figure 9 says people who had more guests at their wedding report better marriage outcomes - even after controlling for income, education, race/ethnicity and religiousness.
Of course, if you want to discard the research and stick with your anecdotes, it was partly funded by a charity founded by a guy who believed in 'strong families'.
You'd probably want to control for wealth to get good data. Marriage duration is correlated with wealth, and wealthy people probably spend more on everything, weddings included.
[edit] nevermind, the the posted link claims the figures are controlled for several factors, including income and education, which both correlate with wealth.
(When the spending is crazy, one must ask what 'for what are they compensating?').