Product licensing, implementation and consulting are onetime costs. Product support, annual maintenance is a recurring and optional cost. Additionally, you can purchase product upgrades, additional consulting and training hours on demand post implementation based on your requirement.
Yes, it is possible to upgrade from one edition to the other at any time.
eContractsTM for SharePoint pricing does not include infrastructure costs like purchasing of servers or SharePoint licenses.
We provide a SharePoint based application and depending on if your SharePoint environment is in the Cloud, or On Premises we will support either type of environment.