Yer they breed Murray cod for stocking public dams and rivers as well as farm dams so they produce 1000's at a cheap price. Although I have seen fish the same size as I brought here for $2ea fir $40.Theyre not insanely expensive, just a few hundred. You need your pond first though and you'd need a lot of equipment just for one fish haha.
Their isn't really a tank big enough for a fully grown Murray cod.