Oh, don't get me wrong, i have no problem against fan art.  It is a fun genre and I think there is nothing wrong with it.  Also, I don't know all the technicalities, I guess it's a lot of "buyer beware".  Alot of my interest is because I do a lot of commercial CG work.  I don't want to get into a problem buying an item I think is an original but ends up being a fan work.  I can get into legal trouble, then the marketplace would get into legal trouble and finally the vendor would get into trouble.

Mrsparky, you are right that the vendor might be unaware or feel perfectly justified selling something he'she spent so much time and effort creating.  I can't blame him/her for that.  Unfortunately ignorance does not excuse the legal implications.

AnAardvark, I believe the comic was called "Roachmill".  I can't cite a specific reference off hand, but I'm sure someone more knowledgeable can clear that up.  I guess in the end there is always the question of rumor vs truth and I might be citing a rumour.

I shy away from using the Daz Troll in commercial work as is because of his obvious resemblance to the Troll from Lord of the Rings.  This is an example of something that makes me say I do not know the technicalities.  I do know that if I release a CG film with an X-Wing, no matter where I acquired the mesh, I'm going to be in an armload of trouble.  I would guess the same for a ship from Aliens or any other major franchise or motion picture.

Fan art is one thing, but commercial work is another and when a marketplace has a license agreement that allows things to be used in commercial work, they should be very careful what they allow their vendors to sell.

APCs, X-Wings, Enterprises and such belong in the freestuff IMVHO.  If a mesh-maker feels he deserves money for his work, then he should be designing something original.