When I picked it up and was putting it in a plastic bag to protect it a woman looked at me and said, "Oh my god, you're not actually going to eat that are you?" I assured her I was and she left with a horrified look on her face. I turned a corner in the produce section and came face to face with the chef/owner of perhaps the best local restaurant. She had the opposite reaction and was as thrilled as I was to find it. She must have bought the remaining heads because it is will be featured at her restaurant this week.
Everything you ever wanted about romanesco and fractal vegetables can be found at this link: romanesco.
I steamed mine for fifteen minutes and ate it with a pot roasted chicken.