public function getFinalPrice($qty = null, $product)
{
    .....
    $finalPrice += $this->getTotalBundleItemsPrice($product, $qty);
    ......
}

public function getTotalBundleItemsPrice($product, $qty = null)
{
    $price = 0.0;
    if ($product->hasCustomOptions()) {
        $customOption = $product->getCustomOption('bundle_selection_ids');
        if ($customOption) {
            $selectionIds = unserialize($customOption->getValue());
            $selections = $product->getTypeInstance(true)->getSelectionsByIds($selectionIds, $product);
            $selections->addTierPriceData();
            Mage::dispatchEvent('prepare_catalog_product_collection_prices', array(
                'collection' => $selections,
                'store_id' => $product->getStoreId(),
            ));
            foreach ($selections->getItems() as $selection) {
                if ($selection->isSalable()) {
                    $selectionQty = $product->getCustomOption('selection_qty_' . $selection->getSelectionId());
                    if ($selectionQty) {
                        $price += $this->getSelectionFinalTotalPrice($product, $selection, $qty,
                            $selectionQty->getValue());
                    }
                }
            }
        }
    }
    return $price;
}

public function getTotalBundleItemsPrice($product, $qty = null)

}
return $price;