Cast iron vs. competition kettlebell — which should I buy?

Per the consensus across BarBend, Garage Gym Reviews, and r/kettlebell, cast iron bells grow in size as the weight goes up and are the cheaper, more durable choice for general fitness, swings, and goblet work. Competition (or competition-style) bells are uniform in size across weights, have a thinner steel handle, and are preferred for cleans, snatches, and sport practice. Beginners doing general conditioning are usually steered toward cast iron.