saw this ad myself, sounds very fishy indeed. for a start you would not want to promote them as having cites + chips as this would confrim that they are from overseas, therefore smuggled. This would eliminate any defense you might have if AQUIS decides to pay you a call (forget fisheries, these guys are the real concern as they will charge you). Sure, there is no law against keeping these, but to have a confirmed smuggled animal is a different kettle of fish entirely.
I would imagine that this is already being investigated as we all know fisheries & co are definitley trawling through gumtree, the shrimp issues are proof of this.
My advice, steer well clear.