Wild shiners in this area are about $20 for a dozen in bait shops. They get them from a few guys who do that for a livlihood.
But you wont get rich catching and selling them for sure.
They use 50# bags of animal feed for chum, and will have numerous bags of it on board their boat along with a very large bait tank.
They first go about baiting the target areas, and later come back and cast net them. But it dosent always go as easy as it sounds.