It's very simple as to why they are consider expensive.
A few reasons:
1. They require wamer temperature compared to other tropical fish (82-85 is ideal). For those in the colder climate, this is a big cost. This is why imported discus from Asia is much cheaper when they leave the breeding facilities. It cost less to grow them out there.
2. Food, Regardless whether you go with home made food or off the shelf stuff. It's expensive. Making your own beefheart or seafood mix isn't cheap either.
3. Water quality....costs of water changes, filtration, ect..
4. There is a lot of time involved in growing discus from frys to adult. The higher quality adult are also a lot more because it has probably been through a culling process. Which leads to reason 5.
5. Not all Discus are equal in looks...the fancier( Colorful) they are, the more they are sought after....thus this makes them worth more.....the eye of the beholder sets the price.
6. Most Discus are hard to tell which is male or female until the act of breeding...which leads back to cost of growing out...see reason 4.
7. There is the cost of shipping that is added at both ends.
8. When buying Discus as with Angels....size matters....so that adds to cost.
9. Retail for discus is expensive because the seller has to make enough to account for loses and stay in business. It's a business.
Hope this helps with reasoning for buying or keeping Discus..
