With the Duke and Duchess of Cambridge attending, Prince George and Princess Charlotte acting as page boy and flower girl, and a roster of famous faces sitting in the church pews (reportedly Roger Federer, Donna Air and Ben Fogle), it is no small leap to assume that a pretty penny will have been spent on Pippa Middleton's upcoming nuptials to hedge fund manager James Matthews.
Indeed, according to experts in wedding planning, next Saturday's event could cost £250,000 (NZD $470,000), almost 15 times the sum of the average UK wedding for 2017, which is £16,842 ($31,500).
The figure, calculated by Bridebook.co.uk, includes detailed costs for catering ($131,000), Pippa's dress ($18,000), a six-tier cake ($4,880), a videographer with drones ($7,500), stationary ($9,600) and bridesmaid's outfits ($4, 230).
The total spend comes to $464,969. And let's not forget that her Asscher-cut diamond engagement ring was said to have cost £250,000 ($470,100).
Hamish Shephard, founder of Bridebook.co.uk, says: "Weddings have become increasingly lavish over recent years mainly due to couples getting married when they are older, and hence being able to spend more, and social media raising everyone's expectations of a wedding."
"Traditionally the bride's parents would pay for the whole wedding, however this is only the case in 23 per cent of weddings now, so it is likely both the couple themselves and the groom's parents are contributing, so Carole and Michael Middleton can breathe easy."
The wedding planning site and app arrived at the total by factoring in analysis of over 170,000 weddings and reviewing 70,000 wedding industry suppliers' prices.
But even with 4,333 other weddings happening in the UK on Saturday 20 May, the one everyone will be talking about - no matter the final costings - will be Pippa's.
Here's what her nuptials might cost, according to the experts at Bridebook:
"Being hosted at the Middleton's family home, with over 350 guests expected, a super-sized luxury marquee is needed as the venue. A luxury 350-person marquee will start at £25,000 but can easily go much higher. With the unreliable British weather in May, a wet weather solution for the drinks reception will also be needed, requiring another marquee, plus a fully-equipped catering tent boosting the price."
"The top luxury London caterers will charge over £170 per guest for catering including all food, chefs and staffing, glassware and crockery hire, and linen hire. A marquee wedding requires an extra level of staffing compared to a permanent venue, which will increase Pippa's catering costs to around £200 per guest, and will comprise the largest cost of the wedding. Luxury wedding caterers, The Admirable Crichton, who hold the Royal Warrant for HRH The Prince of Wales for catering excellence, are likely to be the caterers for the wedding. With over 2,000 canapes and at least 15 chefs required, it will be a busy day for them."
"Giles Deacon is rumoured to be the designer of Pippa's bespoke designer dress. Giles previously designed Abbey Clancy's stunning wedding dress for her marriage to England footballer Peter Crouch which cost $18,000."
"Marquees always require a lot more floristry and decoration than a venue, so luxury florists Lavender Green, the florists for the day, will have their work cut out. On top of this, the wedding florist will include the flowers for the church, plus the bouquet and more. With the wedding hosted in the Middleton's rustic garden, with wild flower meadows and in-bloom purple rhododendrons, expect tall overflowing centrepieces fusing the marquee with the garden. Elaborate table-centres can cost £300 each alone, so with 35 round tables for the guests, the cost can easily stack up."
"We expect around 233 bottles of champagne alone will be drunk to keep the guests topped up during the drinks reception and speeches. This champagne will cost around £9,320, on top of which will be fine wines for the wedding breakfast and open-bar cocktails for the evening."
"Hiring one of the top wedding photographers, including a gorgeous album, will cost around £3,500. Dorset-based Millie Pilkington, the private wedding photographer for William and Kate's wedding, is most likely to be the person behind the lens."
"Without the world's media filming every moment like her sister's wedding, Pippa will likely have a videographer there to capture the day's special moments. Luxury videographers have teams of cameramen to capture all angles, plus usually a drone or two."
"A stunningly-decorated cake from a top cake maker will start from £2,600 and need to be six-tiers to give a slice to each of the 350 guests. The cakemaker is thought to be luxury London-based Domino Purchas or local-Berkshire based top baker Rosalind Miller."
"The wedding will require a number of stationery elements including save-the-dates, the invitation, the Order of Service, the menus, and the stamps! Invitations from a top stationer will cost around £11 each before the other items are included. Mount Street Printers are said to be the chosen stationer."
"From bell ringers and the organist and choirs in the church, to relaxed acoustic musicians for the drinks reception and a top wedding band and DJ for the party, music will be the centre of the entertainment. A top London 6-piece wedding band will cost over £4,250 ($7990) with everyone else on top."
Wedding Rings: $36,000
"Rumoured best man Spencer Matthews better not make the expensive mistake of forgetting the rings. With their wedding rings said to be from Cartier, a diamond encrusted wedding ring for Pippa will cost £15,500 ($29,150) whilst a platinum band for James would be £1,440."
Bridesmaids Outfits: $4,230
"Whilst the bridesmaid's dress Pippa shone in at the Royal wedding cost over £2,000, the average cost of a designer bridesmaids dress is £750. The average number of bridesmaids a bride in the UK has is 3.4, so we are assuming Pippa will have 3 bridesmaids."
Flower Girls and Page Boys Outfits: $3,190
"With Prince George and Princess Charlotte due to be centre stage as flower girls and page boys, Nicki Macfarlane, who provided the flower girl outfits for the Royal wedding, will likely be back on hand. A page boy outfit will cost around £226 each, and flower girl dresses £340."
Church Fees: $860
"Pippa and James will need to pay the church their marriage fees, but whilst this is the most important part of the marriage, it has one of the smallest price tags."
Decoration and Production: $11,280
"For spectacular lighting and production throughout the grounds surrounding the marquee and inside the marquee itself, a top London agency will likely be taking on the job of adding the absolute wow-factor. From bar hire to amazing dance floors, production is key to transforming the blank-canvas of a marquee into something truly jaw-dropping."
"Dashing groom-to-be James Matthews is likely to be wearing a bespoke tailor made tailcoat, waistcoat and trousers from one of London's top Saville Row tailors. A bespoke tailcoat from a top tailor will cost around £4,400 (8,270) alone."
Hair and Makeup: $3,190
"No doubt a top team will be on hand to ensure Pippa and the whole bridal party will be looking absolutely radiant. Hannah Martin of Bobbi Brown and Richard Ward, who also did Kate's wedding makeup and hair for the Royal Wedding, are the top choices."
"Celebrity milliner Stephen Jones is rumoured to be the designer of Pippa's bespoke veil, which will doubtlessly have incredible attention to detail."
"Whilst guests taking photos is expected to not be allowed at the wedding, a photobooth will be an ideal opportunity to capture the guests at their best. Luxury children's entertainers, like London's based Sharky+George who did the Royal wedding, are expected to be on hand to give parents, like William and Kate, the night off."
Wedding Favours: $1,300
"These lovely little gifts for every wedding guest should not break the bank. We expect something low-key and personal, such as a small jar of local honey considering the wild flower meadows that fill the Middletons' garden."
"With James being a previous racing driver, we are confident he has a few friends who can lend him a stunning car to drive himself and Pippa, as a happily married couple for the first time, from the church to the reception, just like Prince William did."
Luxury toilets: $7,500
"With this marquee wedding the luxury toilets that will need to be on hand are unlikely to be the plastic boxes we are used to seeing at festivals. Imagine luxurious bathrooms with gorgeous soaps and fresh linen hand towels. For 350 guests, top end mobile toilets will cost £4,000."