Something like this should bring a list of latest macbooks, but whether that is how the site works I don't know - they might have some sort of reseller account which maybe offers a better api.
PHP Code:
<?php
$url = 'http://www.ebay.co.uk/sch/rss/?_nkw=Macbook&rt=nc&_catref=1&_rss=1&_sacat=175672';
$session = curl_init($url);
curl_setopt($session, CURLOPT_RETURNTRANSFER, true);
$data = curl_exec($session);
curl_close($session);
$xml_data = new SimpleXMLElement($data);
foreach ($xml_data->channel->item as $item)
{
echo $item->title . '<br>'
. $item->link . '<br>'
. $item->description . '<br>'
. $item->pubDate . '<br><br>';
}