For each item, Amazon will get 20 lowest prices in both used and new condition, then sort them into different groups based on condition, fulfillment channel (FBA or merchant), and seller rating. Amazon will then return only the lowest price from each group back to our program. So our program will only display lowest price from each group.
As a result, our program will display the lowest used and lowest new price, followed by the lowest used price from the next 4 used offer groups, and the lowest new price from the next 4 new offer groups.
Usually, each group contains one or two offers, so the program should still give you a good estimate of the market value for this item.
For a more in-depth explanation on the pricing and groups, please read this document online: http://www.asellertool.com/ent/support/AmazonChanges.htm