Bing has a built-in price predictor powered by expedia which can be used to decide and buy your flight tickets cheap.
Whenever we want to check for cheap airfare, we use the Internet travel websites like Orbitz, Expedia etc., But we don't know when the prices go up or down. Making decision on buying or waiting for cheap ticket price is the tricky part.
The Price Predictor in Bing helps in resolving this issue, not 100% but to some extent.
Enter your From and To destination in Bing's flight search. In the results page look at the Price Predictor Tip. The predictor is so simple and more details can be found under the Details & Fare history.
You can set up your fare alert to get emails about the change in airfare.
Nowadays I am using this to book my flight tickets for cheap price. It’s really helpful, try and feel the difference.