Not on the Sandbox. That purpose is to be more of a closed environment and not on search engines whereas I'd hope this to be open to the public.

VB isn't that expensive. A new license is $249, an upgrade is $209.

VB does offer different ways to reduce spam such as the registration process. I started to incorporate a VB forum on my site, but never moved forward it for whatever reason. Can't even recall why any more.