5. Discus fish
Discus aquarium fish are very peaceful. This is one of the main reasons they are loved by many aquarists. You can get Discus aquarium fish for different price ranges, between $230 and $30. The Royal Blue Discuss fish is the priciest aquarium fish in the market today costing approximately $230. The Red Turquoise Discuss aquarium fish is the cheapest and most common attracting a $30 price tag. The fish is more popular than the Angel fish simply because the fish comes in a wide variety of colors.