I charge 60 GBP per hour. 20% VAT is added for UK customers (yeah, sorry 'bout that, guys).
Most repairs take between one and two hours so a cost of between 60 GBP and 120 GBP, excluding parts is kind of average.
If for whatever reason, I'm unable to repair your item, or if in my opinion, it's beyond economic repair a 'non-repair' charge of between 30 GBP and 60 GBP plus VAT will be applicable.