Ronan,
I've been flying overseas long haul and short haul flights most of my working life, and i have never been able to work out even a near calculation for putting bums on seats. I have seen the cost of a seat go up and down for the same flight over the course of a single week, virtually every day a different advertised price.....
Last month i received a special price offer from BA for flights for UK to Larnaca.... The special price was 167 Euros one way!!!! I wrote back on this particular occasion, asking them why i would want to pay 167 Euros each way, to fly to Larnaca, when i could fly to Hong Kong on a five star airline for around 70 Euros more. Needless to say i haven't received an answer, and probably never will.....
In the past, you could save money on flights by pre booking several months in advance, now you would be a complete fool to do that. I now only start looking maybe 3 to 4 weeks prior to when i plan to fly, and sometimes 1 or 2 weeks. So long as your open to fly on any day and at any time, you can save some serious money on the internet and or bucket shops!!
Whatever way you do it and no-matter how much you end up paying for your flight, ....you will never find out the how and why that particular flight you booked came up with the price you paid !!!! It will always remain one of those life's mysteries...lol!!!
David.......