Microsoft provides SharePoint Deployment Planning Services (SDPS) that allow its customers to use their Software Assurance Benefits to cover the costs of engaging with qualified providers for SharePoint deployment and upgrade planning services. You can read more about SDPS here.
As someone who delivers these SDPS engagements, more often than not I have had the need to take the customers through the SharePoint features available as part of various on premise and online plans. While a comprehensive listing of these features is available on TechNet here, it is hard to filter this listing by the edition or plan type thus making it difficult to help them understand the features missing or available between different editions. Without duplicating much effort, I have created a quick excel file and uploaded it here (Updated: May 7th 2014) for your convenience if you too would like to view a filterable feature comparison within the different editions and online plans of SharePoint 2013.
Hope you find it useful