The local salt water shop had one around 1 year ago for sale. It was only about 8" in size and was $1200!!!. It was sold 1 week later. I took a picture of it while it was at the store. If I can find it I will post the picture.
I worked with a few aquarist on a project to try and house them but when we figured in the cost and the out come it wasn't worth the investment even though there a beautiful Ceph. to observe. But for now will just leave them in the ocean and enjoy them in there natural home.