Trying out a new theme on a dev site

Hi, we are looking to purchase this new theme - but would like to build it on a dev site first before migrating to our live site + replacing our current theme - what are our options here?

I think you can do it with any problem. In some cases if you face theme license registration issues then may be you have to deregister from dev then have to register to live site.

Better You can ask your pre-purchase query directly to the theme author by posting comments going through theme Comments page. theme author will answer your query.