get post custom value

I think you can better use get_post_meta();
Your code will look like this:

<?php $site = get_post_meta(get_the_ID(), 'projLink', true); ?>
<?php if(isset($site) && $site != "") : ?>
   <span><p><a href="https://wordpress.stackexchange.com/questions/38943/<?php echo $site; ?>">Visit the Site</a></p></span>
<?php else : ?>
   <p><em>Live Link Unavailable</em></p>
<?php endif; ?>

You use var_dump only for testing purposes (http://php.net/manual/en/function.var-dump.php).