I know, that's why I highly doubt that online fish store would have them available all those years ago, and while I agree that they are very complicated to maintain, they are not so much a death sentence, who buys a fish like those know they need a system with specific features and attention to detail that must be unique to the particular fish, I don't know the Peppermint angel kill rate, but there are many that have been successfully maintained for several years.
Do you have any info on that?
The term 'many' may not have been appropriate because they have only been available on a handful of occasions. Perhaps you are referring to the particular specimen Mr.Urakami has in Japan, that fish is on the cover of the book 'Angelfishes of the world' ', by Kiyoshi endoh, a book that came out several years ago, maybe 2007 or 2008. Someone mentioned on the net that this fish was collected in the 90's but I'm not sure about that, and it was moved a few months ago. I know that Sandler kept a partner for a while, and one of them passed away; Chingchai had one for years, and then it was sold, I have no idea who. Whenever I look at videos of BH I see one available, or I have no idea if it's the same fish or the same fish over the years. Again, these fish have been available on a handful of occasions, when there was a batch of them several years ago, most went to tanks of aquarists in Asia who prefer to keep private.
