I'm not sure whether I can buy advance tickets before boarding. It is recommended that you know the relevant ticket purchase information through the official channels of Sichuan Gong X Automobile Co., Ltd.
As for the bus fare from Chengdu to Gengda, the specific price may vary according to the number of trains, seat type and travel time. According to the information provided, there is a bus at 6:20 every morning, and the fare is for each 32 yuan; 17:00, two shifts every night, and the fare is 40 yuan per shift. You can choose the appropriate train number and seat type according to your travel plan and demand, and inquire about the relevant ticketing platform or learn more about the fare and ticket purchase through the official channel of Sichuan Gong X Automobile Co., Ltd..