And I'm not even considering developing "my own CMS".
Well, maybe you should. At least, think of it as an aready existing wheel: what you want is a CMS. So think of it how a CMS would fix this.
What you should do is consider the "static" page as a template. What you fill into the template is variable content. It can be page blocks: a postprocessed (so you're sure it is valid HTML, for example) version of what the user created.
There are CMS-ish systems on CPAN where you can produce static HTML pages out of user content. You should check those out. For example: Blosxom:
Blosxom can operate as a CGI script or produce static HTML files.