...just to drag up an old topic and add my two cents as an, as yet, unpaid member and experienced web developer and forum admin....
When I first registered on here, it took a week for my account to be approved for me to be able to post anywhere and even now, my posts are still being moderated - not quite the first impression you want to give to new, potentially paying members. I gather this has been done in an attempt to reduce spam but there a far better ways of going about it which won't alienate new members.
I haven't looked hard but I've yet to see anything on how to become a paid member and what, if any, extra benefits there are. Marketing a paid subscription, even on a niche site like this should always be a top priority once a good userbase has been established. There should be links to info on how the become a paid member and what they get in return in every sub-forum and on the main site landing page.
The various web spiders/crawlers like google bot should be allowed to crawl the site and see everything a non-paying member without having to register - because they can't. This will help search engine rank no end and increase new members.
Please don't take offense to anything I'm saying here. I just wanted to give an "outsiders" perspective. If you need help with any of the above (gratis), give me a shout