The most common meat based fish food is mysis shrimp, however raising mysis shrimp in the home isn't an easy task. The larger mysis shrimp that most of us feed are generally a freshwater genus and because they are cannibalistic they will eat the smaller fry. As such you will need multiple tanks (3+) and need to constantly separate and sort the mysis by size to reduce cannibalism.
Other alternatives would be raising silversides, which I would think would be rather easy but you would still have a food costs associated with feeding the feeder fish.
One of the cheaper, and some would argue healthier, options is to make your own fish food. You can buy frozen bags of shrimp, squid, cuttlefish, mussel, and octopus, found in the frozen section of an asian market and just toss it through a food processor, freeze and serve.
Marc has a great article on his site of multiple options for making your own food. http://www.melevsreef.com/food.html