Agile technology curves provide the possibility to compare a SharePoint 2013 on premise scenario with an Office365 one.
Set up time and cost (before Q1): Set up time with Office365 is pretty fast, one has to order the applications and functionalities and everything is ready in minutes. Supposing an on premise SharePoint scenario, everything has to be installed from scratch that takes of course more time. From the licensing point of view usually Office365 is cheaper than SharePoint.
Architecture limit (after Q2): The main different is the architecture limit. With SharePoint 2013 on premise there is still the possibility to extend the framework or integrate external systems with farm level development, sandbox, business connectivity services or custom service applications. Considering Office365 most of the framework extensions are simply not possible; the only way to realize some extension is to develop a provider hosted App, which requires a high expertise and can not be carried out very fast.
Figure 1. Agile technology curve of Sharepoint 2013 on premise and Office 365.