the bus fairs are very strange in devon i have never known such expensive fairs... exeter to sidmouth single ^5.90, this is why i hate having no train station! once im in exeter with my railcard i can get anywhere in devon for ^6.60 on the train with no restrictions after 930 am.... then again you can get a day ticket on the bus for ^6.50, its a shame that there isnt a combined ticket for bus and train, like the dartmoor rover that ticket has encoraged me to stay out of the car many times however paying ^6.50 just to get to the train station......
There is in Cornwall, its called "ride Cornwall" is ^10 (^8.30 with a railcard) and is valid on all trains between Ply-Pnz and branches also on First and Western Greyhound busses in Cornwall only (not Plymouth)