Is There a Ploy Behind Some Open Source Plugins?
Since these plugins are incomplete, the user, already committed to them, will get frustrated and either buy the "pro" version or pay someone (likely the developer) to set it up on a site.
Basically you have to be a programmer or hire a programmer to even make minor adjustments to these plugins. A programmer who is working on a Joomla shopping cart plugin and doing a brilliant job solving an array of problems with this plugin for a pet site of ours, quite frankly states some of these code problems are plain stupid or likely deliberately planted (eg not written properly to call up categories).
Adjusting this shopping cart plugin for an optical site also proved to be particularly challenging, though it was mission accomplished.
My point? I'm not complaining -- just leting you know what you might be getting into when you use a "free" shopping cart plugin.
Project HERE.