From unloading goods come without a price, how to make their price equal to zero and those that have already been added?

Question

1C-Bitrix

Tried like this, but it only works when resaving the product

AddEventHandler( "catalog", "OnProductPriceDelete", array( "CProductEventsHandler", "test" ) );

class CProductEventsHandler
{
    public function test($ProductID, $arExceptionIDs)
    {
        if (empty($arExceptionIDs)) {
            CPrice::Add(array(
                'PRODUCT_ID' => $ProductID,
                'CATALOG_GROUP_ID' => 4,
                'CURRENCY' => 'RUB',
                'PRICE' => 0,
            ));
        }
    }
}