E-commerce is getting smarter and the need for several workers for repetitive tasks is no longer needed reducing costs.  Being a PHP platform the ecommerce software Magento allows scripts to be written for it with the database data.  Scripts can automatically do repetitive tasks and save hundreds of man hours, the only thing you need is a savvy script writer and off you go!  Magento handles everything from the ecommerce shop all the way to invoicing and delivery details, keeping all the documentation on one system reduces errors and again saves on man hours transferring data from system A to system B.

It's important to upgrade your Magento platform as soon as possible from 1.3 as the old version to reduce bugs and common issues.  The new platform also has extra SEO benefits with automated metas and titles.  Some payment modules will not work with old versions of magento so you may find that putting off the update could cost you in the long run, check every module is compatible with the newer version too though!