Thats a good average for some good breeding quality fish Cubby. Some strains because of genetic make up, not nessecarily their color, go for much more. There are two types of "Golden" discus those based with a Pigeonblood gene, and those based on a brown strain gene, the pigeonbloods anyone can get. The browns however are rare and hard to come by. They can be used to enhance colors into an existing strain, but generally aren't sold, those fish however again speaking about a spotted strain, can fetch $1000 for a 4" fish easy, if not more. Thats $250/inch after that size, expect to pay an additional $500/inch due to a slow in the growth of discus, so an adult fish at an average size of 6" for a true spotted golden strain would cost you, $2000.