Maybe I missed a post, but what kind of angel was it? I have seen many fish in this price range, peppermint angels come to mind, they are only rare because they come from more then 350 ft and it is expensive and dangerous to collect, but people who go that deep collect between 6-10 per trip, not a rare fish, just very hard to get. Same is true for genacanthus personatus from HI, only place where they are found reletively common it is not legal to collect them, other places 200-300 feet to find them. But again, not that rare of a fish. Other fish I've seen worth money like that are hybrids, mostly angels, which usually are infertile as the definition of a sp is they have to produce fertile offspring or they are just color varieties of the same sp, look at the debate on hamlets most experts can't agree because they breed in the wild producing 3 "types" of babies, 2 sets look like one or the other adult and a 3rd that is a perfect mix between the adults. and all will inbreed with eachother and all young produced are fertile.
Also, most people willing to spend that much on a single fish usually know what they are doing, most CEO's just want something pretty not super expensive. Fish like that go to Japan where the fish is very well taken care of.