Foreach loop within foreach loop is echoing the array

I am using the cms perch to retrieve data using various functions. I am retrieving product items from various sub pages. The code I have so far is working as it should and can be seen here: http://www.ww.thirdfloordesign.net/products/70mm-couplers/

$raw = perch_pages_navigation(array(
    'from-path'=>'*',
    'skip-template'=>true
));

if (count($raw)) {
    $items = $raw;   
} else {
    // add else statement to output warning 'no products found in this category' or something
}

foreach($items as $item) {
    $product['ID'] = $item['pageNavText'];
    $product['title'] = $item['pageTitle'];
    $product['path'] = $item['pagePath'];
    $product['parent'] = $item['pageSubpagePath'];

    PerchSystem::set_vars(array(
        'product-id'=>$product['ID'],
        'product-title'=>$product['title'],
        'product-path'=>$product['path'],
        'product-parent'=>$product['parent']
    ));

    $product['image'] = perch_content_custom('Image', array(
        'page'=>$product['path'],
        'template'=>'product/_image.html',
        'sort'=>'_order',
        'count'=>1
    ), true);

    PerchSystem::set_var('product-image', $product['image']);

    $items[] = perch_content_custom('Product', array(
        'page'=>$product['path'],
        'template'=>'product/_product.html'
    ), true);
}

Where the data needs to be outputted I am using the following code and it seems to be working as it should except it is also echoing an array which can be seen on the page. Is it because I am using duplicate $variables / array names? Solutions please

<?php
    if (!empty($items)) {
?>
<ul class="product-grid">
<?php
    foreach($items as $item) {
        echo $item;
    }
?>
</ul>
<?php
    } else {
?>
<p class="alert alert-warning"><i class="icon-warning-sign"></i>No products found!</p>
<?php } ?>