Koi fish prices range enormously. Common pet-store koi cost $10–$50 USD (₱500–₱2,800). Mid-grade hobbyist koi cost $50–$300 (₱2,800–₱17,000). Show-quality koi from reputable breeders cost $1,500–$10,000+. The world record is $1.8 million for S Legend. In the Philippines, koi typically range from ₱500 to ₱50,000+ depending on size, quality, and source.

The $1.8 million koi fish, S Legend, was purchased by Dr. Tomoharu Aoki, a prominent Japanese koi breeder and collector. She was sold at the Sakai Fish Farm auction in Hiroshima, Japan in October 2018.

Kohaku koi — white body with red markings — are consistently the most expensive variety at the elite level. S Legend, the world record holder at $1.8 million, was a Kohaku. Gosanke varieties (Kohaku, Sanke, and Showa) dominate top auction prices. The quality of the specific fish matters far more than variety alone.

Ki Utsuri (yellow and black koi) are among the rarest varieties, with very few high-quality specimens available. Ginrin metallic koi with perfect shimmer are also rare. The Yamabuki Ogon with a perfectly uniform metallic gold finish and zero blemishes is considered one of the rarest to find at top show quality.

In the Philippines, koi fish range from ₱300–₱1,500 for common pet-shop varieties, ₱1,500–₱8,000 for mid-grade farm koi, and ₱8,000–₱30,000 for quality local breeder stock. Japanese imports start around ₱30,000 and can reach ₱500,000+ for show-grade specimens. Giobel Koi Center offers koi starting from ₱1,500.

The key factors are: body conformation (torpedo shape, no deformities), skin quality (pure white base, intense red hi), pattern balance and symmetry, color intensity, size for age, breed and bloodline (Sakai Farm, Dainichi, and other elite breeders command premiums), and overall visual presence — what Japanese judges call “showa.”

Top-quality koi from elite Japanese breeders can appreciate in value, particularly Gosanke with championship pedigree. However, koi require expert care and significant ongoing expense. Most serious collectors keep koi for the passion rather than as a primary financial investment. The koi market is also niche and illiquid compared to traditional assets.