Allow Manual Price Adjustment Based on Inventory

<?php
//Code to Allow Manual Price Adjustment Based on Inventory
//Foxyshop 3.3+ required, place this in your functions.php file

//Manual Price Adjustment
add_filter('foxyshop_setup_product_info', 'my_custom_price_setting', 10, 2);
function my_custom_price_setting($product, $product_id) {
    $pricing_levels = get_post_meta($product_id,'_pricing_levels',1);
    if ($pricing_levels) {
        $levels = explode("|", $pricing_levels);
        $current_inventory = (int)$product['inventory_levels'][$product['code']]['count'];
        $setprice = -1;
        foreach($levels AS $level) {
            $current_level = explode("-", $level);
            if ($current_inventory <= (int)$current_level[0] && $setprice < 0) {
                $setprice = (double)$current_level[1];
            }
        }
        if ($setprice >= 0) {
            $product['price'] = $setprice;
            $product['originalprice'] = $product['price'];
        }
    }
    return $product;
}

//Show New Field in Admin
add_action('foxyshop_admin_product_details','my_custom_pricing_levels_meta');
function my_custom_pricing_levels_meta($post_id) {
    $_pricing_levels = get_post_meta($post_id,'_pricing_levels',1);
    ?>
    <div style="clear:both; padding-top: 6px;"></div>
    <div class="foxyshop_field_control">
        <label for="_pricing_levels"><?php _e('Price Levels'); ?></label>
        <input type="text" name="_pricing_levels" id="_pricing_levels" value="<?php echo esc_attr($_pricing_levels); ?>" />
    </div>
    <div style="clear:both"></div>
    <?php
}

//Save New Field
add_action('foxyshop_save_product','my_custom_pricing_levels_meta_save');
function my_custom_pricing_levels_meta_save($post_id) {
        global $post_id;
        foxyshop_save_meta_data('_pricing_levels',$_POST['_pricing_levels']);
        return $post_id;
}