Magento – Event for Adding a New Product

After lot of research I got solution...:-) But we may do this very easily.

public function ratingsUpdate(Varien_Event_Observer $observer)
    {
        $object = $observer->getEvent()->getObject();
        $data = $object->getData();

        $newRatings = $data['ratings'];
        $reviewId = $data['review_id'];

        $newSumRatings = 0;
        foreach($newRatings as $r) {
            $value = $r % 5;
            $newSumRatings += ($value) ? $value : 5;
        }
        $newAvgRating = $newSumRatings;

        $statusId = $object->getStatusId();
        if($statusId == 1) {
            $common = Mage::getSingleton('catalog/common');
            $attribute = $common->getAttribute('ratings');
            Mage::app()->setCurrentStore(Mage_Core_Model_App::ADMIN_STORE_ID);

            $productId = $object->getEntityPkValue();
            $product = Mage::getModel('catalog/product')->load($productId);

            $reviews = Mage::getModel('review/review')
                ->getResourceCollection()
                ->addStoreFilter(Mage::app()->getStore()->getId()) 
                ->addEntityFilter('product', (int)$productId)
                ->addStatusFilter(Mage_Review_Model_Review::STATUS_APPROVED)
                ->setDateOrder()
                ->addRateVotes();

            $avg = 0;

            if (count($reviews) > 0) {
                foreach ($reviews->getItems() as $review) {
                    $temp = 0;
                    if($reviewId == $review->getReviewId()) {
                        $sum += $newSumRatings;
                    } else {
                        foreach( $review->getRatingVotes() as $vote ) {
                            $temp += $vote->getPercent() / 20;
                        }
                        $sum += $temp;  
                    }
                }

                $avg = $sum / (count($reviews) * 3);
            }

            $product->setRatings($attribute->getOptionId(round($avg)));
            $product->save();
        }
    }

I used for this usecase sales_quote_collect_totals_before:

/**
 * Set prices
 *
 * @param Varien_Event_Observer $observer
 */
public function salesQuoteCollectTotalsBefore(Varien_Event_Observer $observer)
{
    /* @var $quote Mage_Sales_Model_Quote */
    $quote = $observer->getQuote();
    foreach ($quote->getAllItems() as $quoteItem) {
        if (is your product of choice) {
            /* @var $quoteItem Mage_Sales_Model_Quote_Item */
            $product = $quoteItem->getProduct();
            $price = whatever formula you want to use;
            $product->setPrice($price);
        }
    }
}

On the client side, you can just use a few lines of JS to update the price?