score:8
TJX includes the CBX charges while TIJ does not.
From linked PDF
When booking a flight to Tijuana-Cross Border Express TJX, the CBX service (closed pedestrian bridge that spans the border between the United States of America and the United Mexican States) will be added automatically in the passenger's final reservation. The boarding pass can be used to board the flight and to enter the Cross Border Xpress, the client must consult the documents required to enter at the www.crossborderspress.com link. In case you have not selected the Tijuana-Cross Border Express TJX station, the CBX service can be purchased independently if the selected route is from / to Tijuana.