In Ubercart auction final bid amount adds sell price instead of highest bid amount in the cart?
/**
 * Implements uc_cart_alter.
 */
function mymodule_uc_cart_alter(&amp;$items ) {

  foreach ($items as $index =&gt; $item) {

   //you can add condition for your bid product

    $items[$index]-&gt;price = 100;
  }
}


For reference:

http://www.ubercart.org/docs/api/hook_uc_cart_alter