The ones that have sold on ebay within the last 2 months have gone in the $200-$400 or so range. Atlantic Aquarium had or maybe still has one in the $250 or so range. The showed up in a couple of different colors with yellow being the main one that come around.
They similar to dendrophyllia(sun coral) but bigger and are in the flabellidae family. They're also listed under gem of the sea or eye of the sea. They're also a lot smaller than they look in the picture.