Where can you buy these?

[whatcaneyedo]

I don't think those are available anywhere. They're probably protected locally, or they're just too large/delicate for collection and shipping. Or perhaps they're accepted as being currently impossible to maintain in captivity due to feeding requirements. Who knows... I'd suggest learning how to culture your own phytoplankton first and mastering regular coral keeping before moving up to difficult Azooxanthellate species.

However if you'd like to try your hand at keeping a small variation I could send you a handful of this one of these days.