I don't think there is an clean way to do that. At least I've found this solution:
>>> print doc('h1').html(doc('h1')('span').outerHtml())
<h1 class="price"><span class="strike">$325.00</span></h1>
You can use .text() instead of .outerHtml() if you don't want to keep the span tag.
Removing the first one is much more easy:
>>> print doc('h1').remove('span')
<h1 class="price">
$295.00
</h1>