How does your license works? Can I buy once and use it in 2 domains?
Mosets Tree extension is released under GNU GPL license. You can find the full text of the license here:
This means that you can install Mosets Tree on any number of websites.
Note that our support is based on per site subscription. Which means when you purchase a site subscription, you are entitled to register a single site in which we will provide support for. If you wish to have support for 2 or more sites, you will need to purchase additional site subscription. You can find more about Mosets Tree's pricing at http://www.mosets.com/tree/pricing/.