Are there buses cheaper than the train?
Forget the bus... train is OK (SNCF), you can have 30% discount if you are under 26 or if you are a student somewhere.
Car is the best option and hitchhiking works well:
Toulouse - Albi: 30 min
Albi - Rodez: 1h
Just stand in Jolimont that way you can get the maximum of people going to Albi... about 10 years ago