Standalone page designed to generate Excel-compatible table with all grouped products' cost and price (per components and total grouped product).

grouped_products_cost_price.php

<?php
include_once "app/Mage.php";
umask(0);
Mage::app();
$layout = Mage::getSingleton('core/layout');
//load default xml layout handle and generate blocks
$layout->getUpdate()->load('default');
$layout->generateXml()->generateBlocks();
//get the loaded head and header blocks and output
$headBlock = $layout->getBlock('head');
$headerBlock = $layout->getBlock('header');
$footerBlock = $layout->getBlock('footer');
echo $headBlock->toHtml() . $headerBlock->toHtml();// . $footerBlock->toHtml();
?>
<div class="page-header">
<?php
$groupedProducts = Mage::getModel('catalog/product')->getCollection()
                                                    ->addAttributeToFilter('*')
                                                    ->addFieldToFilter('type_id', array('eq' => 'grouped')); ?>
<table style="width:75%;">
    <thead>
        <th>Parent SKU</th>
        <th>Child SKU</th>
        <th>Cost</th>
        <th>Price</th>
        <th>Qty</th>
        <th>Total SKU Cost</th>
        <th>Total SKU Price</th>
        <th>Total Cost</th>
        <th>Total Price</th>
    </thead>
    <tbody>
    <?php foreach($groupedProducts as $product) { ?>
        <?php $sumCost = $sumPrice = 0; ?>
        <tr>
            <td><?php echo $product->getSku() ?></td>
            <?php $associatedProducts = $product->getTypeInstance(true)->getAssociatedProducts($product); ?>
            <td>
                <?php foreach ($associatedProducts as $item) { ?>
                    <?php $sumCost += ($item->getCost() * $item->getQty()); ?>
                    <?php $sumPrice += ($item->getPrice() * $item->getQty()); ?>
                    <tr>
                        <td></td>
                        <td><?php echo $item->getSku() ?></td>
                        <td><?php echo number_format($item->getCost(),2) ?></td>
                        <td><?php echo number_format($item->getPrice(),2) ?></td>
                        <td><?php echo $item->getQty() ?></td>
                        <td><?php echo number_format($item->getCost(),2) * $item->getQty() ?></td>
                        <td><?php echo number_format($item->getPrice(),2) * $item->getQty() ?></td>
                        <!--<td><?php echo $sumCost ?></td>
                        <td><?php echo $sumPrice ?></td>-->
                    </tr>
                <?php } ?>
            </td>
            <td><?php echo $product->getSku() ?></td>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
            <td><?php echo $sumCost ?></td>
            <td><?php echo $sumPrice ?></td>
        </tr>
    <?php } ?>
    </tbody>
</table>