Disqus Comment for one role type
in admin/config/services/disqus set the location to block

then in admin/structure/block put the "Disqus comment" block below the "Main page content" 

Now, edit the Disqus comment block, scroll all the way down, under Visibility Settings, click on roles and check mark premium and administrator. 

Edit: 

Unfortunately, you can't remove the comment box. Disqus used to offer a way to do it, but now they don't. 

The only workaround, would be to create a block that is displayed for anonymous users and non premium authenticated users only. 

Then inside that block put css to hide the comment box behind/underneath the article body. 

For Example: 

&lt;style&gt;
 #disqus_thread { z-index: 1; position: relative; top: -180px;}
 .article-body { z-index: 2; position: relative; background: white;}
&lt;/style&gt;


Unfortunately, with this tactic you would lose the comment count and the sort option. Although, you could display the comment count using the views module.