The most eye-catching estimate has given the celebration a price tag of over $42 million. However, it is perhaps fortunate for Meghan Markle’s and Prince Harry’s respective families that one of the many advantages of being royal is the enthusiasm of suppliers to offer one significant discounts.

For although the headline figure has been much bandied about in recent days, and this may indeed be an accurate estimate of the market costs of the different components of the event, the truth is that Harry and Meghan will actually be getting their wedding for a fraction of that price.

The royal family has never been forced to disclose what they do or do not pay their suppliers, but occasionally information has leaked out.

For instance, it is widely known that they pay very little for their fleet of Range Rovers, which are leased to the royals by the company as part of a specially reduced VIP deal.

Holders of royal warrants are believed to sometimes offer their royal patrons significant discounts—or at least trade prices—on their goods, offering further scope for a royal bout of haggling.

Drilling down into the figures reveals a fascinating insight into the biggest day of Harry and Meghan’s lives.

The palace declined to comment. However, sources said that all expenses except security would be met by Prince Charles and the queen.

So what will the wedding of the year really cost—and who will be paying for it?

SECURITY: At an estimated $42 million, the policing operation to keep the royals and the estimated 100,000 visitors to Windsor safe on May 19 is the biggest expense of all, and, for obvious reasons, the tab is being picked up by the state.

After all, it really wouldn’t be cricket to have the happy couple or another member of the royal family assassinated at the royal wedding. And, unfortunately the threat level has never been higher.

Therefore, an unprecedented security operation has swung into action. Police have already begun fingertip searches of Windsor above and below ground, investigated all long and short term rentals and property purchases undertaken in the town since the announcement of the wedding and increased their presence in the town.

The fact that Windsor Castle is, a er, castle, doesn’t help much, as Harry and Meghan have announced they will be taking an open-top carriage ride through the town to show themselves to the town’s citizenry after the ceremony.

All visitors to the town of Windsor will be required to pass through airport-style screening areas—and $1.4 million is reportedly being spent on a counter-drone system alone.

Graham Smith, of the anti-monarchy pressure group Republic, told The Daily Beast: “This is a private, personal event. So yes, they need pay for everything. They’ve chosen to turn this into a PR pantomime, there was no need to. The procession in Windsor will add to the cost and that’s a bill the royals should pick up. So far more than 28,000 people have added their name to our petition calling for government to save taxpayers from any royal wedding costs.”

WHO WILL REALLY BE PAYING: The U.K. taxpayer

THE DRESS: The average cost of a wedding dress in the U.K. is about $2,100, but Meghan won’t be wearing any off-the-shelf number.

Assuming she goes with a high-end or couture designer, and Ralph and Russo who created the dress she wore for her engagement photos are the current hot favorites, she could be looking at a dress worth anything from $70,000 to $140,000.

Katie Nicholl, author of the new biography of Harry, Harry Life Loss and Love, said that Meghan is paying for her own wedding dress but it won’t be anywhere near the $560,000 that has been reported in some sections of the press.

“My sources tell me that Meghan wants to make a contribution to the wedding. She’s a feminist and a wealthy and independent woman and the fact is that pretty much all of the wedding costs are being picked up by the royal family.

“She has been very much in charge of the dress from choosing the designer to insisting on covering the bill herself and I think her mother might also be making a contribution to the dress.

“While it will no doubt be a show stopper of a gown, Meghan isn’t spending anywhere near £400k ($560,000) on it, in fact I would be surprised if the budget is over £100k ($140,000).

“Meghan knows Ralph and Russo and has worn their dresses on the red carpet and of course for her official engagement pictures, so it would fit for them to be making her bridal gown, although I also wouldn’t rule out Erdem. If she is going for elaborate, ornate and eye catching on her wedding day though, Ralph and Russo would be perfect. Their workshop is also very conveniently situated a stone’s throw from Buckingham Palace.”

WHO WILL REALLY BE PAYING: Meghan and her mom, but likely at a heavy discount.

THE FLOWERS: Floral decorations for the big day are estimated by the website Bridebook to cost around £100,000, and wedding planners we spoke to agreed this was accurate.

This is one of the expenses that the royals will likely be required to pay for in full out of their own pockets—however once again, there is an opportunity for costs to be cut significantly if some of the flowers are grown on the queen’s Sandringham estate.

It used to be de rigeur for the family to specially grow all the flowers used for decorations at aristocratic weddings in Britain, a convenient way to boast about one’s extensive grounds and the quality of one’s gardeners and greenhouses while presenting an outward mask of frugality.

The tradition was honored at Kate’s wedding, when many of the floral decorations, including multiple small trees that would have cost several thousand euro, were cut or dug up in Sandringham and taken to London for the event.

WHO WILL REALLY BE PAYING: Prince Charles

THE CAKE: The unusual decision to announce the name of the supplier for the wedding cake for Harry and Meghan’s wedding does not in itself suggest that a special deal was made between London’s fashionable Violet bakery and the royals, but the high-profile endorsement has catapulted the bakery, previously a favorite of east London hipsters, into the mainstream.

However, Bridebook’s estimate of $70,000 for the lemon elderflower cake has been rubbished by wedding planners and housewives alike. “It seems Meghan already had a good relationship with Violet’s owner, Claire Ptak, having interviewed her for her blog a few years back.

“It’s unlikely she would charge more than £5 ($7) a head on a commercial basis, and I’d expect Harry and Meghan to be paying more like £3 ($4) per head, if anything at all,” says a wedding planner who has worked on a multitude of society weddings.

Meghan and Harry have invited about 600 people to attend the chapel for their wedding and a further 2,600 members of the public have been invited into the grounds of Windsor Castle. But the cake won’t be cut until the after-party at Frogmore House—with 600 guests expected, the cake is likely to cost a maximum of $2,800, perhaps half that or nothing at all.

WHO WILL REALLY BE PAYING: The Violet bakery’s advertising budget.

THE VENUES: St George’s Chapel is privately owned by the queen, so Harry and Meghan won’t have to pay to use it, as regular church goers must. Frogmore House, where the after party and reception is taking place, is owned by the Royal Collection, which is the personal property of the queen, meaning a fee is unlikely to be levied.

WHO WILL REALLY BE PAYING: The Queen

LIGHTING, CATERING, MARQUEE HIRE: These costs cannot be cut, say industry sources. Lighting is unlikely to cost less than $70,000 and could rise to $140,000; a glass marquee is around $280,000; and catering for 600 people will require 30 chefs and 60 wait staff.

“Harry and Meghan are very mindful of the costs because Harry’s father and grandmother are picking up the bill,” says Nicholl, but points out that, “The queen has a very efficient events and catering team at Windsor who will be overseeing the wedding breakfast.”

Indeed, with the palace well used to throwing lavish banquets, the royal couple will certainly benefit from their established network of suppliers and staff.

WHO WILL REALLY BE PAYING: The Queen and Prince Charles.

DRINKS: Companies which have supplied senior royals for over five years can be rewarded with a Royal Warrant, and when it comes to Champagne, the royals are well served, with nine different brands of Champagne holding royal warrants.

Competition among them to be represented at the wedding is likely to have been fierce. Bollinger has enjoyed a close association with Britain since 1858 and prides itself on having held a Royal Warrant continuously since first awarded by Queen Victoria in 1884.

Bolly was served at the weddings of Prince Charles and his brother Prince Andrew, but not at Kate and William’s nuptials. Will they be able to break their run of bad luck and get back in the royal enclosure?

“They shouldn’t be paying a penny for Champagne as it’s one of the things that always gets reported by the press,” says one marketing executive. “They might have to pay for the wine.”

WHO WILL REALLY BE PAYING: The alcohol industry’s marketing department

TRANSPORT: A significant cost for most people getting married, conveyancing won’t figure as an expense for Harry and Meghan, thanks to Her Majesty’s extensive collection of carriages and horses. Expect to see a fleet of Range Rovers (see above) ferrying guests from the car parks to the reception at Frogmore House.

WHO WILL REALLY BE PAYING: Given that the Royal Landau dates from Queen Victoria’s reign, these costs were sunk long ago.

THE RING: Harry will almost certainly marry Meghan with one of his mother’s diamond rings. These are owned by the Royal Collection, which is owned by the Monarch of the day, and are effectively loaned to the recipient for their lifetime, so the ring won’t cost Harry and Meghan a penny.

WHO WILL REALLY BE PAYING: The Queen.

THE SPICE GIRLS: Whether or not Mel B and the girls will perform on May 19 is shrouded in secrecy, but one thing is for sure—the marketing value of performing at Harry’s wedding would guarantee a sold out world tour, so the estimated $7-$14million cost of booking the Spice Girls definitely won’t apply.

WHO WILL REALLY BE PAYING: Ticket holders for their global gigs.