Interesting to me that there are so many varieties of Tilapia introduced. They are one of the more common forms of farm raised fish and can be raised with very low start up costs. I've seen them sell in live tanks in Hispanic markets for $6/pound. For under $1000, you can start your own system and they are sometimes raised along with hydroponic crops such as basil or leaf lettuce.
New 1000 gallon Tilapia 'grow out' tank! - YouTube
New 1000 gallon Tilapia 'grow out' tank! - YouTube