Even a hand-picked style of bouquet takes time and expertise conducted by a top-tier floral designer, so that the bouquet holds up well during photos, and during the ceremony.
The types and numbers of flowers, especially if the bouquet will include some exotic, unique or pricy blooms, adds much to the cost of the bride's bouquet, particularly if hers will be larger than the bridesmaids' bouquets.
The higher cost of organic flowers factors into the cost to a fair degree, as does unique greenery that can sometimes cost as much as flowers, depending upon the style chosen and its availability. Brides often learn a lot about the floral industry and how weather conditions and disasters in overseas or domestic growing spots can hoist the cost of flowers.
Your floral designer will need to order far more flowers than are needed for this important bouquet, to create lots of options for the best-looking blooms to be used, and the others either discarded or used for other projects at the wedding, like flower petals.
You're also paying for the expertise, location and reputation of the floral designer and his or her assistants, affected as well by overhead costs of the floral designer's storefront and marketing.
And of course, the bridal bouquet is an emotional purchase and an important part of a bride's wedding dream. The emotional weight of a wedding bouquet leads to its garnering a higher price point as well.