man that sucks. Looking at those skeletons pains meI've had my most expensive coral for nearly four years at this point, I bought it for a price I'm still unwilling to disclose and at a reasonable size for the coral species in question. It started out blood red with a striking green rim, then slowly evolved to a more suffused pinkish gold color, until finally one day it turned invisible! In fact, all of my other corals of that species turned invisible at the same time, and the neat thing about invisible coral is that you can keep it above water to display on a desk. SO that's what I do. In total, this pit of invisible corals ran me $1,200. And now, I don't even have to go downstairs to enjoy them! They just sit on my desk.
Satire aside, Acanthophyllia is my favorite coral, and also the most consistently expensive genus in the hobby. However, they absolutely HATE warm tanks and do best at temps below 72f. I ran my tank at 80f, so it was only a matter of time before the heat got to them. It's sad, but you live and learn.