I have read about Tilapia and I would guess they are legal. I'm not sure on the cost of Tilapia but I know they would have to be restocked every year.
Tilapia breed readily in captivity. In fact, if you had room anywhere for a small aquaculture set up you could breed your own every year and it would cost next to nothing.
You could grow about 250 tilapia up to about a pound and turn them out in the pond in the spring. They will spawn like crazy.
