well I live in the middle of america, so all the coasts (new york and cali) all get fish cheaper since thats where the planes usually land. When I went to florida the fish were generally half or less than what they are where I live.
I think I saw a huge beautiful oscar about 14 inches for 20 dollars in florida, and here that would have been 80.
Cheapest I can find a teacup stingray (reticulated ray) is 100 dollars while some are sold at wal marts in different parts of the country.
Some wal marts have discus as well. It all depends on the location.