Magento 1 - Where does Magento Set a Quote Item's Price?

Dug this one up myself. So there's this

#File: app/code/core/Mage/Sales/Model/Quote.php
foreach ($this->getAllAddresses() as $address) {
    ...
    $address->collectTotals();
    ...
}    

which leads to this

#File: app/code/core/Mage/Sales/Model/Quote/Address.php
public function collectTotals()
{
    Mage::dispatchEvent($this->_eventPrefix . '_collect_totals_before', array($this->_eventObject => $this));
    foreach ($this->getTotalCollector()->getCollectors() as $model) {
        $model->collect($this);            
    }
    Mage::dispatchEvent($this->_eventPrefix . '_collect_totals_after', array($this->_eventObject => $this));
    return $this;
}

The getTotalCollector object returns a sales/quote_address_total_collector object, which loads a series of collector models from global/sales/quote/totals and calls collect on them. The sub-total collector's collect method ultimately calls this

#File: app/code/core/Mage/Sales/Model/Quote/Address/Total/Subtotal.php
protected function _initItem($address, $item)
{
    //...
    if ($quoteItem->getParentItem() && $quoteItem->isChildrenCalculated()) {
        $finalPrice = $quoteItem->getParentItem()->getProduct()->getPriceModel()->getChildFinalPrice(
           $quoteItem->getParentItem()->getProduct(),
           $quoteItem->getParentItem()->getQty(),
           $quoteItem->getProduct(),
           $quoteItem->getQty()
        );
        $item->setPrice($finalPrice)
            ->setBaseOriginalPrice($finalPrice);
        $item->calcRowTotal();
    } else if (!$quoteItem->getParentItem()) {
        $finalPrice = $product->getFinalPrice($quoteItem->getQty());
        $item->setPrice($finalPrice)
            ->setBaseOriginalPrice($finalPrice);
        $item->calcRowTotal();
        $this->_addAmount($item->getRowTotal());
        $this->_addBaseAmount($item->getBaseRowTotal());
        $address->setTotalQty($address->getTotalQty() + $item->getQty());
    }    
    //...
}

and this is where the quote item gets it's price set/rest.

From a high level, the code that starts the whole process are lines 464 and 465 of Mage_Checkout_Model_Cart :

 $this->getQuote()->collectTotals();
 $this->getQuote()->save();

The new product price is being set against the quote in Mage_Sales_Model_Quote_Address_Total_Subtotal in the _initItem method. You will see $item->setPrice in the the if / else statement starting at line 104