Koi are a big deal in Japan, where they have all sorts of cultural significance. So a $1 million-plus price for a national grand champion show winner is not uncommon. Unfortunately, the colors don't breed true, so the offspring of a fish that has won for its coloring will produce a myriad of different colors, thus the offspring aren't guaranteed to be show quality. But given that they are very long-lived in captivity when well cared for, the $1.8 million championship fish could outlive its owner and maybe even its owner's great-grandchildren. The longest-lived koi attained a documented age of 226 years before dying in 1977.
Still lusting after an immense koi pond in the back yard... I subscribed to a koi magazine for many years...