I was able to price out itins continuing to TIJ from all of the major cities in SA for this fare (SCL, EZE, LIM and GRU) and TIJ added anywhere from $50-$200, but for the budget traveler, it might help. There is a shuttle that Volaris runs between TIJ and the downtown SD train station (Santa Fe Depot), and a cab to the border crossing in San Ysidro isn't that pricey either (cross the border and grab the trolley). Unfortunately, neither the trolley, SD Coaster nor Amtrak actually connect to any airport, requiring additional bus, cab and local train rides to get there.