If you are considering individual fish in the price range of several hundred dollars each, you should insist on seeing photographs before you buy. Koi dealers will provide you with Polaroids showing the specific fish and their prices — if they are convinced you are serious. When the photos arrive, you can look them over, select the fish you want and then call the dealer to finish the purchase. I strongly advise anyone who is considering buying expensive fish to insist on seeing pictures of the actual animals first. But don’t expect such service for inexpensive koi.
expensive fish or koi are specifically ordered, probably from abroad.
You can get koi with good colors and nice shapes for far less if you check with local koi clubs. Members always have fish for sale. Even spending $100 for an average specimen is considered inexpensive by many koi enthusiasts. Here again, I recommend starting out with young, ordinary pond-quality koi. These still have beautiful colors and might cost $10 to $20. Learn how to take care of them before you consider trying to match the pictures you see in books. There is nothing like coming out to your pond and seeing your $7000 prize koi floating belly up on the surface to ruin your interest in koi keeping.
Why are Koi fish expensive to buy and keep in captivity
Many of the really expensive koi are expensive, not because of their genetics, but because they are less than one in a thousand. Colors are genetic, but the exact placement of them on the fish are largely random. Fish with certain desirable patterns cost a lot more because a thousand or ten thousand other fish may have to be raised up with them to find that fish with a perfectly symmetrical pattern, or a pattern that suggests something from Japanese history or mythology. Depending on how interested you are in Japanese culture may decide whether you place that same value on that fish, or if you should let someone to whom it means more become the owner.
Just How Much Are Koi Fish? — Koi Story