hes not referring to buying a cup of them and feeding the fish, hes talking about actually raising them, keeping them.
me personally, i'd neverrrrr ever do that because they are supposed to be absolutely filthy to raise, very unsanitary. i rarely even feed my fish live worms anymore, they are so gross half the time that they are filled with parasites, frozen is always sterile. now i just give them live worms like once a month as a treat.