I have 10 widgets (facebook, disqus, twitter, etc.) that I can add to a site when I am designing it. Is it okay to charge for adding these things to the package?
Without knowing any of the details, I would say yes, it is legitimate to charge for anything that adds value to a customer's site.
If you're worried about pushback from your customers, then you need to sell them these features as things that they need. It's all in the marketing.