economicalec·o·nom·i·cal /ˌekəˈnɒmɪkəl, ˌiː--ˈnɑː-/ adjectiveadj using time, money, goods etc carefully and without wasting anyAdults generally watch a movie on video once or twice, making it more economical to rent than buy.
Environmentalists insist that polystyrene recycling can be economical.