I know a woman who makes several thousand dollars a year selling dried flower wreaths in San Fran. Not her main enterprise, but nothing to sneeze at either. I'm not so sure a simple bouquet would be as popular, as you can't hang it on a wall and forgitaboutit. I guess you could stick it in a vase and forgitaboutit...but it's not as out of the way as on a wall.
I had this idea for making wreaths that double as seed sowers. As in, enjoy the wreath all winter, then toss it outside and it'll make a flower patch! Most dried flowers do not retain their seeds....so I was thinking about ways of sneaking seed balls or something into the wreath. The lady I mentioned uses wire and styrofoam as the hidden base, and that obviously would not go so well with my idea. I made a bunch of bamboo wreath skeletons...and never got further.
She grew specific varieties for the wreaths, flowers that dry sturdily. Baby's breath,
straw flowers, eucalyptus branches, etc.