Many people love to brag about saving money. But for self-made millionaire Ramit Sethi, there are some things in life that are worth the splurge — and one of them is your wedding.

"I want to share my experience, having gone through planning a wedding with my wife just a few months ago," Sethi, a personal finance expert and author of "I Will Teach You to be Rich," tells CNBC Make It.

"Let's be honest," Sethi says. "It's your one special day....You want the nice flowers or the nice chair or the nice chicken. Why not? It's your one day.

"My advice to you is acknowledge it, plan for it, don't delude yourself into thinking that you are only going to spend $16 on a wedding."

The average cost of a wedding in the United States is at least $33,000, according to XO Group. That total includes everything from venue costs to food and alcohol, entertainment and the bride's dress.

For that reason, you need to start saving now, says Sethi.

Factoring in the age at which people tend to get married, as well as your own income and ability to save money, you should be able to come up with an idea of how much to start putting aside immediately to finance your dream wedding down the road.

And don't feel like you need to wait until you're engaged, or even in a relationship, to start saving, Sethi says. While some people might feel awkward saving for a wedding so prematurely, Sethi feels the opposite way.

"I think it's weird to not save and to wait until you're 28 [or] 30, and suddenly you say: 'My god, where is this money coming from?'" he says.

Sethi, who is 36, got married in July. He'd actually been saving for his wedding since he was 24 years old, several years before he even met his wife, he tells CNBC Make It.

Long before he was ready to get married, Sethi says, he knew two things for sure: "I knew, one, that I was probably going to get married eventually. Two, I knew that it was going to be a lot more than $30,000, because I'm Indian." (Indian weddings are notoriously extravagant and, even in the US, they cost roughly $65,000 on average, according to one estimate.)

"So, I started saving money every single month in a savings account — I literally called it 'Wedding Savings' — every month I would put money [in] there automatically."

Over the years, Sethi kept putting money into the savings account, while keeping a separate allotment within that account for an engagement ring, he says. When it came time for him to propose to his then-girlfriend, he was able to start budgeting the eventual wedding costs. (Sethi has said previously that you can ignore the old rule of spending two months' salary on an engagement ring. In reality, you should make a budget that makes more sense for you.)

"I logged into my wedding savings account and said, 'OK, great. So, this is the basic parameters, this is how much I know we have to spend,'" he tells CNBC Make It.

"There are a lot of things about weddings that are not intuitive," he adds. "Everybody says just keep it small and simple. And, if that's what you choose, awesome. I love that. A lot of people have small, beautiful weddings — amazing.

"But when it comes time to get married, you have to realize it's not just about you. You have a lot of dynamics that are at play. You've got your husband or your wife's family, you've got other family members that need to come, maybe you need to pay for them to fly in."

In other words, Sethi says, it's important to sit down with your partner and come up with a plan for wedding expenses that you're both comfortable with and that also takes into account the aspects of the wedding that are most important to you and your family — whether that's springing for the nicest flowers, paying to fly in a family member or whatever.

"As someone who [has] planned a wedding for over 230 people, and who knows what it takes to save and plan, just be honest with yourself..." Sethi says. "You're probably going to spend more than you think.

"Plan for it, build that [savings] account right now, get on the same page with your partner, make sure you have a vision for what that wedding is."

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