If the flowers were both of Cephalotus 'Eden Black' there is a very good chance they will look similar to the parents, it more unlikely you would get something else. That said, the plant would NOT be a Cephalotus 'Eden Black' I don't care what happened.
It would need to be labeled Cephalotus 'Eden Black' x or Cephalotus 'Eden Black' x 'Eden Black' depending if there were 1 or 2 parents.
Back to the original topic you could probably get alot for even one seed IF the person buying/trading for them believed they were the real deal. However, get a seedling and it would be 100X more, get a seedling that looked like a Cephalotus 'Eden Black' and well...Just keep it labeled correctly.
---------- Post added at 04:26 PM ---------- Previous post was at 04:24 PM ----------
Thus the 2 ways to label the crosses.