I don't have a GS (any more), I have just sold a bike in the non-GS section.
I've bought and sold stuff that's unrelated to GS ownership here too.
If you think that GS's sell cheap here and that the subscriptions are a way of keeping such "cheap" sales in-house, you're sadly mistaken. In fact the prices here are often inflated because member's bike's are sometimes well known and the provenance is worth extra as well as the safety net that comes from knowing that it's unlikely that someone will sell a pup and hang around.
All the points about allowing non-subs paying people to view the FS&W sections have been trotted out over the years and they've failed to convince. Nothing has changed.