less performance limited selection limited selection one-ninth to one-fourth the payload one-ninth to one-fourth the payload expensive According to Winslow Wheeler $120 million $20 million expensive less performance less performance $120 million $30 million range $120 million $20 million less performance less performance one-ninth to one-fourth the payload one-ninth to one-fourth the payload $30 million range limited selection $30 million (£18.7 million) range expensive $120 million one-ninth to one-fourth the payload $20 million one-ninth to one-fourth the payload less performance limited selection $20 million $20 million $120 million expensive $120 million $120 million less performance $20 million one-ninth to one-fourth the payload $20 million