Anything I make that requires so much time, especially when design time is at a premium, I price high. I generally tell them $50-$75. If they bite, great, I will at least make some profit. If no, fine, at least I didn't just turn them down. That is the key.
To save time, make the BB ring in as much advance as you can, spray WELL with crowning glory, let dry, bag, and put in cooler. 1 week ahead of time is just fine. Then, the day before, glue the roses in with Oasis cold glue. Cut the calix all the way to bud until it is flat and spread that whole thing with glue and let sit for a couple minutes. At the same time, dot your glue into the BB ring, deep in next to wire and tape. If you let the glue cure on both the ring and the rose for a couple minutes, and then put them together, I guarantee those roses are going nowhere!
Good luck!
Linda