These containers are not really 'made' ATM. They're artists' renderings (and maybe shots of prototypes) and nothing will get manufactured until the winners are selected. The flowers are just photoshopped on top.
IIRC in consumer testing, the flowers had minimal affect on consumer choices (since the featured 'designs' are always dome shaped or clumped.) The containers and colors were what swayed customers into like or dislike.
On a $39.99 SRP, the COGs target should be in the $12 range. With the container at $4.99 (and really mosts florists pay $5.99 plus another $1 for shipping), there's only $5 left for flowers and foliages (if you plan to make any money on them.)