I have in the past paid a fair bit for good quality japanese koi and mostly they have been with me long enough to be classified as vintage. Had a lovely Ogon that a mate imported for me, it was with me for 28 years. Bit like Fenders, the japanese ones are usually damn good.
Haven't spent much money on Koi in recent years, my last purchase, a rather lovely Kohaku about ten years back.
I've stopped buying Koi mags and don't go to near the koi dealerships anymore.