They're one of more well-known "rare" fish avaiable. They range from $150-300, so pricey, but not absurd as some angels or wrasses. I love this species .... big gaudy fins, completely velvet black, long snout.
How long have you had him? You must be very confident to pay that kind of money for a fish. I've been in this hobby for 4 years now and I still cringe at a pricetag like that.
Guy's been in my tank for a while. Fish generally don't die under my care unless another fish decides to eat it or chase it out, so with some careful mix-n-matching, I have pretty good confidence that they'll be around for a while.