All upgrades are included for one year starting on the date of your initial purchase, regardeless of whether subsequent licenses were added to your account later on. After the first year, you can renew the update service for an additional year at any time.
The current price for the renewal is computed from your number of licenses. The base price is 249$ for the XLGL Personal Edition (or your first 2 licenses in case of volume licensing), then 100$ per additional licenses. For example, if you own 5 licenses, the renewal cost will be 549$ (249$ for the first 2 licenses, then 3 X 100$ for the additional licenses).
Prices are subject to change.