Google Product Feed (by WooCommerce)

if (class_exists('WOOCS')) {
    global $WOOCS;
    if ($WOOCS->is_multiple_allowed AND $prices['sale_price_ex_tax'] == 0) {
        $prices['price_ex_tax'] = $prices['regular_price_ex_tax'];
        $prices['price_inc_tax'] = $prices['regular_price_inc_tax'];
    }
}