Why is the insurance at Deutsche Allgemeine always the best?

So an example: DA – German General: 1,203,37 € 300 € / 150 € (UK / TK) KRAVAG-Allgem. Vers.: 1,461,99 € 300 € / 150 € (UK / TK) R+V: 1,603,99 € 300 € / 150 € (UK / TK) That’s almost always so – always the DA is significantly cheaper than others! Sometimes 50 Euro, sometimes 150€, sometimes 200€ etc. – no matter how much, always cheaper. Is there anything different than with others or are they really always cheaper?