school holidays always cost more as everyone wants to fly then. In the past it's often been best if you can wait until the last minute to get unsold holidays cheap. Now (they say) this won't be the case any more... but I must admit they always say that, in the hope of persuading people to book early so they've got your money for as long as possible. As nobody really knows how the economy (ours or Spain's) will be going next summer, you might like to take a chance and wait. Or you could try taking your 6-year-old in term time; I shouldn't think it'll damage his A level prospects.