I've recently started work on my first Drupal 6.x Theme.

The Hunchbaque base theme, which I usually use to construct new themes for Drupal 5, has not been completely ported into Drupal 6.x so I had been searching for alternatives. Hunchbaque while adequate for Drupal 5 just isn't ready yet to start making a theme in Drupal 6.

I've recently found the Framework Theme which is promising to the point a new theme I am developing for Drupal 6 has reached the point of 20% completion in a couple of hours.

Here's a preview of work done in just over 2 hours:

drupalroyale2hours

I estimate the time taken to build a new theme for Drupal 5 or 6 based on pre-made designs would be about 4 hours for the most basic theme if the theme was built using the backbone of the Framework Theme.