Visual Composer in Wordpress site design?

I have WordPress installed on my server and am thinking of buying a plugin called Visual Composer. I will be buying a Regular license, which means, as it is stated non their site, i can only make on site with it.

What does that mean? How many designs can i make for my site and sub-sites? What if i were to have multiple landing pages on my server with just different sub domains and each having a completely different design? Will the regular license be enough?

Thank you for you're help!

via Chebli Mohamed