you could get there easily with cutting out pieces of stiff fondant with flower cutters, texturizing and adding outlines by piping and adding some fondant dots & stuff
layer them onto the cake
let them set up with motion--where you lay the cut pieces on flower formers
and onto pieces of aluminum foil that are bent around the way you want
so the flowers dry 'in motion'
the ones that lay between the tiers you'd want to dry carefully in those positions
or do them as you lay them on the cake
put them on with a nice dollop of icing or melted choco on the back so they stand up away from the cake
i'd say $5 to $6 a serving in my area
it's not super complicated or anything the way i'd do it
(making exact molds yes would be much more)
it's a bit more than a standard wedding cake in my opinion--i mean i already have those types of cutters too
fondant covered cake would be additional
y'know maybe up to $7 in buttercream or so
i haven't really looked seriously at my prices in a few years
somewhere around there is where i'd go