Here is our list of veneers which could be considered ideal for balancing a panel to prevent warping. The JoeWoodworker website has an article discussing the use and need for balance veneer. Click here to learn more.
Other low cost veneers can be found by arranging the display order of the veneers in any category. Use the sorting menu near the top of the category listings to show the lowest priced veneers or those which have the lowest grade. These are often the best options for balance veneer.