Carnegie Mellon University to Western Michigan University buses and trains from $42

Here are some trips other travelers have found on Routefriend.
$42
13h 10m
2 stops
Greyhound Amtrak
$82
13h 0m
1 stop
Greyhound
$104
18h 16m
2 stops
Amtrak
$145
14h 16m
2 stops
Amtrak Greyhound