North Hollywood, CA to Tijuana, MX buses and trains from $39

Here are some trips other travelers have found on Routefriend.
$39
6h 45m
1 stop
Amtrak GotoBus
$47
5h 21m
1 stop
Amtrak GotoBus
$48
5h 21m
1 stop
Amtrak GotoBus
$76
13h 3m
2 stops
Amtrak GotoBus