A couple other legitimate options you may want to look at:

1. Check with your employee benefits. A lot of the licensing agreements that companies have with Microsoft include a provision for free or discounted Windows license through your employer. Not everywhere has that, but it's not super rare either.
2. If you are a college student and have a .edu email address, you can sign up for Azure for Students, and you'll generally have access to Windows license through that. To access them, you have to navigate to the Education>Software menu blade. Once again though, what is offered to you here can vary depending on your college's licensing agreement with Microsoft.