We're trying to book a holiday for summer 2017 as a surprise for our DD (16) and our DS (14). She will have passed her GCSEs by then, and they both have wanted to go forever... last week we saw flights London NY return at £500 each, and that just about made it possible for us to afford it. By the time we searched airbnb and made our mind up the flights have gone up to £700 each, and that is a stretch... DH thinks that means we have missed the early bird offers, but that there WILL be sales and we can wait and see... I fear at this point prices will only go up and we should get the £700 while we still sort of can, or risk missing out on the trip altogether... so million dollar question: does anybody know how the price structure works and is there a chance that prices will go down nearer the time, or should I start looking at holidays in Cornwall? 
can anyone recommend low cost sites to follow prices on? Any other suggestions? Thank you!!!