BOSTON (CBS) – Buying an airline ticket seems a little like playing the lottery. Every now and then you hit the jackpot and score a great fare. Then the next day, the price can be hundreds more.

Figuring out how the system works so you can improve your odds can be confounding, however. As one traveler at Logan Airport said, “Sometimes it is really hard to understand, as a person who is flying, how they come up with their prices.”

Another passenger added, “I think it varies every single time, to be honest with you.”

WBZ-TV’s Paula Ebben reports

Anne Banas of www.smartertravel.com in Charlestown explained the airline industry uses a system known as “Yield Management” to figure out how to price their tickets. “They are always trying to see who is buying, who is selling, which are flights are going, which aren’t on a given route. And they can adjust their prices.”

Landing the best fare might be as easy as making sure you book on the right day of the week, added Banas. “A lot of airlines will release sales on Monday,” she explained. “Then the other airlines will match, so that is going to be your optimum time to get the best deals.”

We decided to try it ourselves and checked prices, over several weeks, from Boston to Tampa, Chicago, and Los Angeles.

Monday, in our unscientific survey, did turn out to the best the best time to buy a plane ticket.

Looking at round trip fares in December, we found significant savings following this strategy.

For example, a JetBlue flight to Tampa would have cost us $348 if we reserved on Thursday, but just $198 on a Monday.

We would have shelled out $166 to get back and forth to Chicago on Spirit Airlines if we purchased our ticket on a Sunday. On Monday, it was down to $138.

A Los Angeles to Boston ticket would have cost $398 on a Wednesday, but was available for $338 on a Monday.

Although the temptation can be to hope you will keep getting a better fare, Banas cautions against waiting too long. “I always say you want to get a good fare. You’re not necessarily always going to get the cheapest fare available. You want to get something in your budget and you want to feel like you got a discount, so don’t play it too much.”

Another suggestion to get a price break on your ticket is to be flexible with your travel dates. For example, it is often cheaper to fly on a Saturday morning, than on Friday.

Also, before you jump at what looks like a great fare, consider the fares for that airline. For example, if you are going to check baggage, any savings on the base fare can disappear quickly if that airline charges a lot to check bags.