Let's start of with a few basics. All the airlines publish their fares. So, if you go to them directly, you know exactly how much you are going to be asked to pay. That said, there are "high" and "low" seasons where the volume of traffic rises and falls. Airlines do offer "sale" prices to maintain passenger volumes during the low seasons. Some increase their prices at the peak periods. Then you have the budget carriers. These offer basic carriage at a basic price. All this information is usually freely available and gives you the base price to work from.
