Stamford, CT to Princeton University buses and trains from $26

Or, see buses and trains from Princeton University to Stamford, CT.
Here are some trips other travelers have found on Routefriend.
$26
2h 36m
1 stop
Metro-North Megabus
$40
2h 34m
1 stop
Amtrak Megabus
$63
4h 55m
1 stop
Amtrak Amtrak