Well, there's good news ... and more good news! Joomla! 1.5 is free, it is released under an Open Source license - the GNU/General Public License v 2.0. Had you invested in a mainstream, commercial alternative, there'd be nothing but moths left in your wallet and to add new functionality would probably mean taking out a second mortgage each time you wanted something adding!
Joomla! changes all that ...
Joomla! is different from the normal models for content management software. For a start, it's not complicated. Joomla! has been developed for everybody, and anybody can develop it further. It is designed to work (primarily) with other Open Source, free, software such as PHP, MySQL, and Apache.
It is easy to install and administer, and is reliable.