When you save a product in Magento’s backend admin console application, the system will reindex the price information for that product.
But when you use $product->save() then that product will don’t update immediately to frontend, concrete is in list in search result
//index for change product
$resourceIndexPrice = new Mage_Catalog_Model_Resource_Product_Indexer_Price;
After, reload and get result
Thanks for whatching!