Here is a nice little hack to filter or sort products based on discount or offer for ubercart module in drupal 6.

In drupal, ubercart module provides 3 types of price fields that can be entered for a product - Cost price, List price and Sell price. Here the sell price is the final price at which a customer can buy a product and it is a required field. To sell a product at discounted price we uses list price and sell price fields. Here the list price will be the price without discount...