Euskadi 2014 flights
Some flight info.
I fly from Stansted to Bilbao on Easyjet.
They are now taking bookings for July 2014.
I have booked and it cost £244 (£54 for the rifle transit, £12 for insurance and £31 for luggage)
From experience Easyjet flights tend to get more expensive closer to the date. However, they do occasionally have sales.
Hope this helps