A method and system is provided for making price-related predictions of items based on training a classifier using historical information including pricing information for the items and labels relating to the price-related information that are generated automatically from the historical information. A prediction system provides price-related predictions for airline tickets. The prediction system collects flight information for flights on a daily basis. The prediction system generates training data to train a classifier to make the price-related predictions using the flight information. After training the classifier, the prediction system then can make the price-related predictions for a trip.