I've just been on
www.ba.com, and if you choose your dates carefully in Jan, you can get a BHX-EDI-BHX ticket for £55 INC TAXES!!
Yep, but BA's cheapest fares restrict you to taking 6kg of hand-baggage -- you have to pay extra (or 'increase the flexibility of your ticket') if you are taking hold luggage. On the plus side though, there is a CHOICE of complimentary newspaper for all ticket types! Worth all of 30p. Wow.