TagsPage Directory is a Web 2.0 script which had huge success, much more than I imagined it'll have. It made and still makes me a lot of money from little work on my side, since everything is automated. Also, the profits return each year, after the tags expire. The script is custom built. You'll be able to recover your investment in no time with good marketing (my profits are in the $xx,xxx zone). The price includes installation and some small changes of look (add your colors and your logo). I'm also open to do customizations to your script. Google seems to like this script since it gave PR6 to the homepage and PR5 to all the free tags pages. Since the PR update the sales skyrocketed to more than $x,xxx/month.