Peak District-cheap trains to London?

[L0uise14]

I'm moving to the (beautiful) Peak District. Which town/village should I live in to benefit from the cheapest trains to London?

I was looking at living near Chesterfield/Sheffield/Derby but trains from there to London are v. expensive (unless you book up ages in advance). If drove for an hour to get out of the Peak District, do you think I could find a cheaper train to London?

why don't you Google journey planner and put in journeys from various stations to London - probably st pancras and check out prices that way?