California Polytechnic State University-San Luis Obispo to Oakland, CA buses and trains from $39

Here are some trips other travelers have found on Routefriend.
$39
5h 22m
0 stops
Amtrak
$46
6h 25m
2 stops
Amtrak BART
$47
6h 46m
1 stop
Amtrak BART
$47
6h 25m
2 stops
Amtrak BART
$48
9h 25m
4 stops
Amtrak BART
$52
8h 40m
2 stops
Amtrak BART