Things You Cannot Affect
You see, the airfares have always been the most complex travel part. It depends on to many constituent parts, which reflects to the overall costs. First part what comes in mind is a fuel price. Depending on circumstances and configuration a Boing 737 consumes 1000 - 2000 US gallons/hour. And the price for the fuel depends on the price in the market - commodity exchange. Therefore, if the changes in the fuel price are like in 2007-2008, then you can imagine how this relates to the airfares. They become unpredictable. Unfortunately these are the things, which you cannot affect.
Things You Can Do
No matter what any advertisement promise there are always the same, very simple, steps you can make in order to squeeze out the lowest airfare available. The first things you should do are to visit some of the major online booking engines and to find out, which is the cheapest flight you can get there.
You will find that there is a direct effect between any online booking engine and lowest airfare possible. The flight with the lowest airfare most likely will be the cheapest flight from other resources as well.
Now that you know the flight details, you can search for the lowest airfare available. There are actually two resources, which can give you the lowest airfare possible. One of it is the airline itself and the other is airline consolidators.
The first thing you should do is to search in the airlines website for the same flight. You will discover that most of the time it is dramatically cheaper than in any online booking engine. It is because airlines do not pay commission to travel agents. Therefore, in order to make some money travel agents should add some fee on top of the net price. However, there are also other things, which you need to take into account.
The airline consolidators make things more complex. They buy large volume of tickets from the airlines, and therefore, they get cheaper prices than on the airline website. Airline consolidators are the ones, which are selling tickets to travel agents. In this case travel agent earns some commission, but still can hold the price level the same as in the airline website.
Therefore, if you see that airline website do not offer a lowest airfare available, you should contact your travel agent. The commissions and fee level in the online booking engine is defined, and you cannot do anything about that. However, with the travel agent you can always agree about the airfare. This can save you up to 10 percent from the publicly available price.