I think you'll have a hard time getting people to list the value of their collection on an open forum. It's just not a smart or safe thing to do.
Here's an example of what can happen:
http://forums.collectors.com/message...hreadid=807775
I'm not sure if I buy the whole story as it was told, but it just doesn't make good sense to let strangers know what you have. It would be like starting a thread asking how much money you have in the bank.
At least that's my $.02