Buy Parallels Plesk Expand
All new license purchases include one year of Software Update Service (SUS) that entitles you to version upgrade licenses throughout the life of your SUS. You will be required to renew this annually to continue the service.
Note: Plesk Expand can manage both Plesk for Windows and Plesk for Linux/Unix servers, but you need to have at least one Linux server to install the Plesk Expand control panel. Please also read the detailed requirements.