Modifying Marketpress to Remove E-Commerce Functionality

I want to be able to allow my users to enable / disable ecommerce functionality. How is this best done? I could just hide all ecommerce functionality in the templates using display:none; but that is a little hacky. Is there a majical plugin for this? I don't want to modify the core code because I want to be able to easily upgrade the platform. If no plugin is available, I could write my own plugin but don't want to re-invent the wheel either. Suggestions???