Depends on their size, American or Japanese, fancy or not. Is your pond set up and seasoned? You should talk with Hank. I have had a koi pond for over 25 years. Hank is knowledgeable and has health fish. Too many diseases out there; be certain of your supplier!
The guy right after me is right on the money. It's a lot to think about. Also don't forget choir fish get eaten by animals all the time. I don't think buying an extremely expensive fish for school makes a lot of sense. But a lot of really cool fishes that are significantly cheaper than koi. Up to you though.
Google search Connies Pond & Koi and there are pictures of different type of koi fishes with price tag or label. All of the fishes they have to offer got a picture and a price on Google.
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