Complex sentence: These early import CETMEs are quite rare, and robust, and fetch a price approaching 5-6 times that of a Century CETME primarily due to the very poor quality and reputation of the Century product rather than actual quality of the MARS guns.
Split into simpler sentences: These early import CETMEs are quite rare and robust, and fetch a price approaching 5-6 times that of a Century CETME. This is primarily due to the very poor quality and reputation of the Century product rather than actual quality of the MARS guns.