I used to have the same problem (and still do - for that matter!) my solution to the issue was to switch to using ASP.NET with a template engine and then using Macromedia to design the site & make it look good.
The site would be backed with a simple database table, and I created a drop-in admin section that would allow them to edit the database fields.
If you want, we can license you the software - it was developed as part of:
http://www.imjustblank.com and it's quite simple to use.
Mind you it requires a Windows Server and MS SQL to run. Nonetheless it means I can develop a fully-fledged site in under a week and allow the user to do the content updates themselves.
This elliminates the need to charge per hour for updates.
The more clients you get the less likely you'll be able to keep up with all the updates, so switching to dynamic content is innevitable in the long run
Cheers,
Martin.