After chopping and discarding the waste, red cabbage averages 45 cents a cup.19 But broccoli sprouts—if you make them yourself—may be even cheaper. Broccoli sprout seeds can be purchased online or at natural foods stores for about twenty dollars a pound, but that makes about seventy-five cups of sprouts. In terms of sulforaphane content, that may be around three hundred cups of mature broccoli. So DIY broccoli sprouts provide a green-light sulforaphane source for about a nickel a day.
