Charging extra for content management for WordPress pages using custom templates
I've got a website with about 5 pages using custom templates. In each of these pages, the content is divided into several blocks each with its own style. For example : an array of data here, a sidebar with informational content there, a big quote below, then a long three-column text, etc. All of this on the same page. So there's no way to have it all in the WordPress dashboard editor. It HAS to be stored in custom fields, editable with meta boxes.
My client thinks everything on the site should be editable from the dashboard, and it should be free. But as a developer I see that this requires a lot of work (creating custom fields and their meta boxes, displaying these fields in the page templates, etc).
My question is : do you guys often find yourself in this situation, where a client requests the ability to content manage a page where the content is not one block of text but many? If so, do you charge extra for such ability?