The experienced and skilled floral professional is able to create the most beautiful displays but you do have to pay for their talent.
The answer to what you pay for is pretty straight forward. The cost of flowers reflect the following, supply v. demand, availability, overhead costs of suppliers, shipping, geography & seasonal availability, and rent. So many things factor into the cost!
If you want to save on flowers, just try to find a floral designer who has the best design experience, & someone who’s work you trust. Ask them to buy what is best this week at the flower market. (this is the place where world wide growers bring their goods to market, rather like a farmers market ). But remember that if you just have to have that special flower, designed a special way, delivered tomorrow then you may have to pay for the service of that level.
Give me a bit of notice, and a bit of flexibility, & I may just be able to save you a bit of money!