It's up to you to monitor your sales and make sure you do not exceed what you have licensed. You can always come back to us and get a new license for additional units. If it's an exact reorder without changes, our fee is half-price. This makes it easy for you to license only what you need upfront and avoid paying too much in fees for reorders.
For Custom Licensing, we must charge our full fee for every request, including reorders.