Hey There,
Thanks for writing in!
You can setup a unique domain name (my-site.dev) using MAMP virtual host and then you can use it to validate your product while you’re developing on your local server. Please refer to this article on how to setup a domain on MAMP :
http://blainsmith.com/articles/quick-and-dirty-local-domain-names-for-mamp
Once you are done with it, you can unassign the license from this site and reassign it back to the live site with the same Purchase code.
Hope this helps!
Let us know how this goes!