I would guess that, since the benevolent host of the forum is in the business of selling new AND USED parts, facilitating other people, possibly in that same business, is probably not a high priority and perhaps somewhat discouraged?
Of course, one might say, "It's just a few spare parts sold from a residential garage", but what I've seen on some other forums, was steady growth of the subsection, until there is a constant parade of health supplements and marketing services being offered. Is this how we want to spend our limited bandwidth? Pity your moderator, if so.