Probably cost almost a million to look that simply elegant. (Reminds me of Dolly Parton's famous line, "It costs a lot of money to look this cheap.") Seriously, they must have needed three refrigerated tractor-trailers to bring in that much greenery and roses, both all around the inner doors, columns and altar and also surrounding the huge entryway and stair rails— and and put them all in place at the last minute so they would be fresh. Wonderfully well done. I imagine Kate had some input there. Both her wedding and her sister's wedding florals were ethereal.
They no doubt had a small army attending just to flowers ;-)
(I liked the little bouquets for the bride and little girls, too.)