This is free for personal PC, but how to use it for organization? Where to buy it from? What is the cost?
If you want to use Bellarc Advisor in an organization, you will have to send an email to the developer as specified on the official website. Use the following email address and contact the developer stating that you want to use the software in an organization: email@example.com
Additionally, check the official products for commercial purposes on their page: http://www.belarc.com/products.html