Hi Snoopinc,
It's really tough to make money from forums and hard to kick start them as well with users and content.
I have recently added a forum to one of my domains (www.hiking.com.au) and I employ a company called
http://kickstartyourforums.com/ to use their writers to write content to help 'kick start' them, admittedly, it's not the best writing you will ever see, but starting to get some pages indexed and increased exposure within the SERP's.
As for what your domain is worth now, I'd say, what you paid for it, but once it's built, indexed and getting PR and users, it will be worth more.