Audiences across the world watching Meghan Markle marry Prince Harry on Saturday are expecting romance and pageantry, including diamond-studded tiaras and 21-foot-long dress trains. But such memorable opulence doesn't come cheap.
While the average U.K. wedding costs about $37,000 (£27,000), a considerable figure in and of itself, England-based luxury wedding planner Aimee Dunne tells CNBC Make It she estimates that, before security, the wedding of Prince Harry and Meghan Markle will cost $2.7 million (£2 million). A whopping $40.1 million (£30 million) more will be dished out on keeping the betrothed and their guests safe, reports U.K. wedding site Bridebook.
Here's how the expenses break down.
With 600 guests attending both the lunch and dinner receptions, plus 2,640 guests from the public who will be provided with tea and a hot snack on the grounds of Windsor Castle, Dunne expects the food and beverage to amount to a quarter of the total budget.
"There will be lots of champagne and whiskey, I'm sure, for Harry," she says.
While the prince and soon-to-be duchess don't have to pay to rent out St. George's Chapel or the Great Hall, there are rumors that the royals are building a glass marquee for the reception. The construction and delivery could cost as much as $400,000, according to Dunne.
The latest front-runner in the question of what Markle will wear on Saturday is a dress from Ralph & Russo, London haute couture designers which have previously prepared outfits for stars such as Gwyneth Paltrow, Angelina Jolie and Beyonce. Ralph & Russo supplied Markle with the dress she wore during her official engagement photo shoot.
The Telegraph reports that the dress will cost in the ballpark of $135,000, but Dunne expects it to be as much as $270,000. That's standard for royal weddings. It is rumored that Harry will wear something more "low-key."
Markle is also expected to change her outfit in the evening. Kate Middleton, the Duchess of Cambridge, wore an ivory satin gown with a diamante belt and matching bolero after her reception, reports The New York Times.
Given the size and scale of the wedding, hiring a team of florists to decorate Windsor Castle will be costly. "It will be tasteful. I don't think it's going to be overly kind of glam and wasteful in terms of what they spend," says Dunne, "but even in that case ... they could easily spend £100,000 on flowers."
Other considerable expenses include entertainment. "The music will be under the direction of James Vivian, director of music, St. George's Chapel, including the Choir of St. George's Chapel, and a selection of choral groups, soloists and musicians," Kensington Palace announced.
So far, Karen Gibson and The Kingdom Choir and 19-year-old cellist Sheku Kanneh-Mason are confirmed performers for the wedding service. There are also rumors circulating that stars such as Elton John, the Spice Girls, Ed Sheeran and Adele could perform, reports GQ.
As for the couple's wedding rings, the bands are reportedly made out of their Welsh gold, reports Bridebook, and there is a chance that Prince Harry follows in his brother William's footsteps and doesn't wear one at all.
Markle's engagement ring was designed by Harry himself using a central diamond from Botswana and two flanking diamonds that belonged to his late mother, Diana, Princess of Wales. Experts estimate the ring could be worth as much as $350,000.
Finally, the cost of logistics can add up, says Dunne, especially for a high-profile wedding where many preparations are made under wraps. "Keeping things quiet — that has a cost associated with it," she says, because secrecy tends to require extra people and more time.
The royal family announced that it will pay for the "core aspects of the wedding," which include the "church service, the associated music, flowers, decorations and the reception afterwards." Markle is reportedly expected to pay for her wedding dress herself.
The cost of security, including snipers on rooftops and a counter-UAV system, will top $40 million, Bridebook estimates, and is expected to be borne largely by taxpayers. For the 2011 marriage of Prince William and the Duchess of Cambridge, the English public paid an estimated $27 million, which allowed for thousands of extra police officers at the event.
That's why the campaign group Republic, which calls for abolishing the monarchy, garnered over 30,000 signatures for a petition calling on the government to disclose how much taxpayer money will be spent on the wedding. "Taxpayers should not be funding a private wedding, no matter who is getting married," the petition states.
Others argue that, considering the attention and tourism that the royal wedding attracts, the event will pay for itself. "I've certainly had more American couples this year who want to get married in castles," says Dunne.
In any case, she believes the ceremony is worth its price tag. "The monarchy for this country is a great thing," she says. "It has an awful lot of positive factors, more so than negative in terms of costs, for sure."
The royal family did not respond to CNBC Make It's request for comment.
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