The forum has never been free; There has always been a significant cost to provide this service, and for the past 20 years Brian has paid that cost. To the end user it has been free, and like many formerly free services there will be a significant loss of users when a subscription, or pay-to-play mechanism is applied.
Regarding the classifieds; There are other places to buy and sell goods and if the cost proposal that is implemented is too much for the seller to accept, then they will post their products elsewhere which will further reduce traffic on the site.
As to the impression that some have regarding the quality of the content; That is to be expected, over the years the sport has changed, new techniques and equipment have been developed and the learning curve is starting to plateau. While there may be a few small things to learn as the sport heads towards its 50th year, I suspect that there is nothing new of consequence around the corner.
This is a treasure trove of information, and a window into the history of the sport, if it folds then I hope that there is some way to archive all this knowledge.