As an unlimited add-on, UpdraftMigrator Premium can be installed on an unlimited number of websites – so there’s no reason to buy more than one copy. 

Buy as a subscription to get 12 months of support. We can do more to support your WordPress migrations with Premium than is allowed via free support in the WordPress forums. We can do things like take a copy of your site (minus the user data) to replicate any errors you may be experiencing or access your server configuration. 94% of tickets are responded to within 24 hours.