Drupal is a powerful free and open source Content Management System, its easy to forget that it is very popular (over 6000,000 users) with only WordPress and Joomla eclipsing its popularity. One of many popular Drupal Themes marketplace for Drupal user and fans is ThemeForest. At ThemeForest you can buy and sell site templates and themes to skin popular CMS products like WordPress, Drupal and Joomla.
It is not just wastage of time but Drupal is definitely worth trying out, it has a lot more customization options and chances to add different features, which even mighty WordPress cannot handle. So, enjoy the beautiful themes collection.