A licensed user is entitled to any updates and/or new versions, free of charge, for a period of 12 months from the date of purchase. When the time of free updates is over the update check will give a message that for a new version a payment will be required. The current version will continue to work even if you don't want to update.
The following screenshot shows the update checker which the message that the new update will not be free:
If you click on the Cancel button the update will not be done and you can continue working with the current version. Clicking on proceed downloads the new version. After installing and starting the new version it will revert to trial mode for 10 days. Both the main window and the Setup will show the same button with red text "License is expired. Click here to renew your license."
After clicking on the button the shop will be loaded with a reduction of 40% off the full price. The rest of the purchase is identical to a normal purchase.