Other than what Venti said, no real problem. Another minor one might be that stuff stays listed even if a char is deleted - but I don't know if that's the case or not, and presume it isn't.
Part of my neat side would like to see *some* kind of time limit. Doesn't have to be a short one like it was in SWG (and yes, those were a massive PITA), but just plain having one would "clean house" now and then on defunct (for whatever reason) listings.
That said, paying money to someone who doesn't exist anymore has got to be one of the better money sinks out there.
