I usually make bookings well in advance. Last May I had to travel to Scotland at very short notice due to family illness. It was a Friday - generally accepted to be the most expensive day to travel. I was returning on the Monday. I checked every airline and every route from the south of England to Scotland. EasyJet and Ryanair were both charging about £200 return. BA & BMI were £300+ on all flights. Eventually I settled for a drive to Birmingham where I got a return flight with FlyBe to Glasgow for £88 including tax.