NEW YORK (CNN/Money) – Here's a great way to alienate people: Suggest they're spending too much on their wedding.

You might ask them how many times in their lives they've ever spent $3,700 or more an hour for anything. (That's about the size of it given that your average wedding costs $22,360 and usually lasts six hours.)

Or give them reams of unscientific proof that no matter how perfect a couple's pricey day, they still face the same chance for divorce as the next duo.

Before World War I, a formal wedding accounted for one-third of the national average family income. By the mid-1960s, the cost had grown to half. And today, it accounts for roughly two-thirds, according to Katherine Jellison, an associate professor of history at Ohio University, who is working on a book about the commercialization of weddings.

And everyone who lives on the coasts or some other pricey enclave know their tabs are likely to be higher.

But you know what? Costs be damned, I love a good wedding -- lavish or not. (And if I'm in just the right mood -- which, granted, is rare -- I don't even mind the bad ones. Throw in enough serious yuck and before you know it you've got absurdist comedy.)

While no one should ever mortgage their house for the privilege of throwing one, the truth is a wedding "is the only occasion when you can experience guilt-free binge consumption," said Cele Otnes, coauthor of "Cinderella Dreams: The Allure of the Lavish Wedding." "It's socially sanctioned to spend a lot of money."

Sure, it's easy to be judgmental. But you really can't put a price on a couple's desire for a certain kind of event or their enjoyment of it. Only they, ultimately, can say whether it was worth it or not.

But I do think you can say the money spent on a wedding is an utter waste when the couple getting married show real signs of going up in flames long before anyone lights the unity candle.

So I talked to three seasoned wedding professionals to find out what they've learned over the years from couples who've crashed and burned, either before or soon after the big day.

After all, "planning a wedding is a good barometer of how this ship is going to handle the winds blowing in your direction. There are a lot of storms," said JoAnn Gregoli, owner of Elegant Occasions in New York.

Here's what they said.

Flowers, check. Invitations, check. Heart-stopping insults, check. There are countless ways to say "I love you." "You look like hell" isn't one of them. That's what one client told his fiancée when she returned from her hair-and-makeup trial, Gregoli said.

Neither is "I don't care what you think. I'm going to get what I want." That was the way another client resolved a wedding invitation dispute that almost brought her to blows with her fiancé.

You say spontaneous. I say rigid. Spontaneous, rigid ... let's call the whole thing off. Jean Picard of Jean Picard Wedding Consulting in Ventura, Calif. has only had two clients cancel their weddings in 11 years. (The experiences taught her to rely on her intuition. If she gets a bad vibe, she won't book a couple.)

She knew one of the couples wasn't going to make it when, during a meeting with Picard, the highly animated bride-to-be, who did most of the talking, said, "We're very whimsical people."

Looking at the groom-to-be, who was decidedly not animated, Picard thought, "Honey, that man doesn't have a whimsical bone in his body."

Smile for the camera! Oh, not you. You shouldn't be in the picture. Photographer Ann Billingsley knew all was not well with the couple du jour when the bride said not to photograph the groom's family too much, and noticeably grimaced every time she was in a picture with them.

More amour, por favor. Not everyone loves public displays of affection. But if it's your wedding day, it's hardly wild-child-crazy to throw your arms around your new spouse and, you know, look happy.

"There have been brides or grooms who have been so tense, I can't believe they're getting married," Billingsley said.

Granted, every relationship has its quirks – or as is often said, the rocks in her head fit the holes in his. But the wedding professionals agree: without mutual respect, affection, communication and a healthy dose of shared values and humor, those tens of thousands of dollars for dinner and dancing might be better spent elsewhere.

And don't think canceling the wedding will save your financial hide. You can kiss those deposits goodbye.

"You can't cancel because of fights," Gregoli said. "If you're canceling because you don't get along, you should've seen it coming."

Jeanne Sahadi writes about personal finance for CNN/Money. She also appears regularly on CNNfn's "Your Money," which airs weeknights at 5 p.m. ET. You can e-mail her at everydaymoney@cnnmoney.com.