Any autobuy link should be prefaced with some kind of disclaimer.

I would even just say that all non-bitcointalk URLs in the Marketplace child boards should have the landing page, with particular emphasis on how ranks don't equate to trust. I believe part of the factor is still that Newbies are unaware of two major differences in this forum: scams are not moderated, and rank titles mean nothing. Until this is displayed in bold letters when you sign into the forum or until there's something to lead people towards this realization, I don't think Newbie problems are going to end easily. A slew of new scam accusations popped up as well regarding off-site deals via external messaging channels - though users should know better - concerning that hole in knowledge and I'm sure that it's more prevalent in the cases that aren't publicized.