You could try theses sites :-
i would recommend this site :-
use sidestep.com. It searches all other websites at one time for the best fares
there are quite a few sites that you can search that will likely give you the best prices available. just go here: http://bookme.com/ and you will be able to compare prices on all the reputable travel sites in just a couple minutes. it's very convenient and will save you a bunch of time and money. Also, make sure you buy them online... otherwise they charge much higher fees for phone orders. good luck.
it's a site that tells you how much flights go for and which travel site has the best deal.
If you buy a ticket, verify with the airline if they credit you back if the price goes down but you already bought your ticket (many of them do).
You can always track your flight's price at:
Some good search-booking engines for cheap flights are:
Airfare.com (+/- 1 day option)
I would check out bookingbuddy or travelzoo. You could also check cheaptickets or you could swarm for it at eswarm.
See http://www.travelbargainsites.com for good travel sites.
Try this site... www.sidestep.com We use it all the time at work