Accessing "0" inside SimpleXMLObject in PHP

Question

I am running some queries against an API that will return an XML string, which I then convert to a SimpleXMLObject in PHP. The problem I am having is I can't access certain values. I will have a very strange structure that won't let me access the values I need. Here is an example of the output of one of the objects.

[totalCostOfFees] => SimpleXMLElement Object
                    (
                        [0] => 0
                    )

How would I get the value of that? I have one that is...

echo "<pre>";
print_r($var);
echo "</pre>";

<pre>Array
(
[26105] => Array
    (
        [rate request] => Array
            (
                [success] => 1
                [cost] => SimpleXMLElement Object
                    (
                        [0] => 30
                    )
                ...

I can get to the "cost" section, but I am always left with array(0 => 30); I need the value, not the array. Obviously I can't use

$variable[$id]['cost']->0; // that will fail for obvious reasons

and I have tried..

$variable[$id]['cost'][0];

But that gives me an empty array. Please help, it is driving me nuts. Thank you.