[cflsystems]

To add to the above - one more file needs to be edited in order to preserve list prices if variants are turned on/off or deleted

Open /modules/Product_Options/func.php and find

        $data = array(
            'productid'        => $productid,
            'avail'            => $_product['avail'],
            'weight'        => $_product['weight'],
            'productcode'    => $sku,
        );

and replace with

  $list_price = $vars[$old_variantid]['list_price']; // added by CFL Systems to preserve list_price for variants
 
        $data = array(
            'productid'        => $productid,
            'avail'            => $_product['avail'],
            'weight'        => $_product['weight'],
            'productcode'    => $sku,
   'list_price'  => $list_price, // added by CFL Systems to preserve list_price for variants
        );

If using BCS mod for variants with orderby sorting that needs to be added there instead - bug in the mod

  $orderby = $vars[$old_variantid]['orderby']; // added by CFL Systems to preserve orderby for variants - BCSE mod bug
  $list_price = $vars[$old_variantid]['list_price']; // added by CFL Systems to preserve list_price for variants
 
        $data = array(
            'productid'        => $productid,
            'avail'            => $_product['avail'],
            'weight'        => $_product['weight'],
            'productcode'    => $sku,
   'orderby'  => $orderby, // added by CFL Systems to preserve orderby for variants - BCSE mod bug
   'list_price'  => $list_price, // added by CFL Systems to preserve list_price for variants
        );