Updates are free and are downloaded from the Download page. When a new version of the software is released, that is version numbers change from 1.X to 2.X (for example), then there is a cost. It basically then is not an update but a major revised version.
From another thread Lloyd stated:
"I have always used a minor/major approach in my software companies. All minor upgrades (3.0 to 3.1, for example) are free. Major upgrades are purchased (3.0 to 4.0). ……….."