I am looking for a light-weight starter kit I can purchase that will allow me to build a lightweight social application. I am particularly looking for this to provide the basic plumbing around users, user profiles, friends, favorites and private messages between users. This is pretty standard stuff and I don't want to reinvent the wheel. The solution needs to be built on top of ASP.NET 2.0 or later.

So CommunityServer 2008 is certainly one option but with its new $5K price tag per server, I am looking for other alternatives. Is anyone aware of any solutions like this? I appreciate your feedback.

Regards,
Johnny