Fly me to the moon ...

Can someone explain to me how the airlines determine their ticket prices? I seriously do NOT understand.

I would like to buy a ticket to go down to do field work this spring, but I just can't commit.

Below is a graph from kayak.com (cool travel website). You see that the X- axis represents a given purchase date from September until today. The Y-axis, also called the "dependent axis" represents the cost of a plane ticket. Yes, as you see, the COST is DEPENDENT on the DAY that one might purchase the ticket. How can the cost change based on day of purchase?

Nothing else changes about the flight or the traveling. The exact flight costs $400 one day and $600 the next? But it is THE SAME FLIGHT. Same departure, same plane, same destination, same too-small seats, same crappy food, same annoying flight attendants, SAME FLIGHT.

I, being a bargain shopper, can understand if the lower price were due to a SALE. For example, sometimes, a 12-pack of diet coke is on sale 4 for $10. Regular price is $4.99. When I go to the store, I expect to pay $4.99 and get happy when there is a SALE. I don't go into the store, wondering what price diet coke might be at today. It is set, and sometimes it goes on sale. And when it is on sale, the sale lasts at least a week. Or at least 3 days. And there is an ad. It's published, therefore, it is official.




Why do we allow this, people???