it depends on your website traffic, is it PR or just new, if it is considered new then you need to get something for your site to have value to show.
Given that the content is unique and that you'll build at least SOME traffic to the site, you'll probably find someone willing to pay you a few hundred for it at Flippa. I personally wouldn't pay more than $25 for it. P.S. Forget everything I said above in case the theme is pirated. (not saying it is - too lazy to check)