Hello,
Currently, if you purchase Start11 its lifetime license for Start11 V1.x and all its update will be free. But, if there is a major change in Windows OS and Start11 need to have major work done for it to work with Windows of that time. Stardock might release an upgrade version. Usually it will be Start11 V2.x etc. This usually, will be paid upgrade. Discount normally will be given for previous version owner.
Thanks
Basj,
Stardock Community Assistant.