A couple of years ago I used the train / bus to get to Alton from Blackpool, had to be at Blackpool North for a 05;45 train to Manchester Piccadilly, then got on a train from there to stoke. When you get to Stoke, there is a bus stop right outside the station that takes you to a place called Hanley. From that bus station there is a direct bus to Alton which you can buy a return ticket for around £5.
Your other option (and IMO the better one). Do the same to get to Manchester but go to Uttoxeter rather than Stoke Train station, there is also a bus stop there, and the bus via Uttoxeter take you direct to Alton. it's all the same on the return journey too, I think the last bus leaves Alton around 6pm.
I had a 16-25 rail card but from what I can remember it cost me,
Around £25 for the train from Blackpool to stoke, about £3-4 for a return to Hanley, then about £5 return from Hanley to Alton.
As I said though, if you get the train to Uttoxeter you miss Hanley all together so you save a few squid.