Microsoft Movie Maker is offered at no charge and is part of Windows Essentials 2012.
If you have purchased what you believe to be Microsoft Movie Maker from a non-Microsoft third party site, cancel your credit card payment, manually uninstall the software, and run a scan of your virus checker.
Windows Essentials 2012 is free; there is no paid or trial version.
As of this morning, January 17, 2017,
Windows Essentials 2012 download offline installer (Microsoft site) is still available.
Windows Essentials 2012
Support Ended January 10, 2017
Windows Essentials 2012 contains the following programs:
Photo Gallery (Windows Photo Gallery 2012 Build 16.4.3528.331)
Movie Maker (Version 2012 Build 16.4.3528.0331)
Windows Live Writer
Windows Live Mail (Version 2012 Build 16.4.3564.1216)
OneDrive
Release Notes on Windows Essentials 2012:
https://support.microsoft.com/en-us/help/13785
It would be wise to download and save a copy of Windows Essentials 2012 (Offline Installer) to a separate disk as backup.
Windows Essentials 2012 (Microsoft Offline Installer) wlsetup-all.exe:
http://g.live.com/1rewlive5-all/en/wlsetup-all.exe