All other factors being equal the least expensive first-year premium payment is found in

This would be the Annually Renewable Term. This is the most pure type of term insurance. The death benefit is always the same but the premiums go up each year that the insured gets older. In policies that decrease, the face amount decreases but the premium is always the same throughout the entire contract. In both level and increasing term policies, the premiums remain the same for the entire policy. All this in mind, with other types of level policies, the premium on the first year would be the same as all other years.