you are experiencing the infamous drupal deep learning curve... once you get it... you will love it...
have you try using magento ? is the most interesting looking one that I have seen so far. www[dot]magentocommerce[dot]com
Most of them are good, some are great. It depends on your level of experience. Wordpress is pretty out of the box easy. Joomla is great, a little more exp req. eCommerce is free, if you have a host that offers it, or you know how to install it, it may be a better solution initially.
If you're a biginner, then wordpress....but i woul strongly recomended learning Drupal. There is no other CMS that offers you so much control ower the users...So...Drupal is the right way to do it
For ecommerce the best is Magento, you can also use wordpress and use some plugins and then there is Zen cart also which is quite easy