Actually, these are the only names I invest in right now, and the only names I actually have a clue about the value. I have over 15 forum/forums/talk names, around 5-7 of them are top quality.
They go usually anywhere from mid $xxx to mid $x,xxx. They are a great investment as well.
I've looked at the years 2002, 2003, and even 2004, and forum names went for low $xx. For example, I had a forum name "htmltalk.com", which in 2004 sold for $20:
http://www.namepros.com/domains-for...g-net-clubbed-org.html?highlight=htmltalk.com
Now in 2005, I sold it for $500 very easily, I could've probably tried even targetting high $xxx but was more desperate for the money. I had 4 beautiful offers for $xxx, so it wasn't luck.
I wish I can show you all these transactions, but they are on a forum which I am not allowed to post on NamePros which I think is ridiculous. The same goes with designforums.com, in 2003 it was in an auction and top bid was $29. In January of 2006 it sold for $4400. So there you go, these names are on a HUGE rise.