So, while I agree that some kind of reaction was necessary, a perma-ban takes it much too far, IMO. Especially as this is a beta and similar problems have been reported for a long time now, with no reaction other than "set up RDMS right".
The way this whole mess was handled by NQ so far (among some other things) shows me that NQ seems to totally lack experience and understanding when it comes to MMOs, how to deal with your testers (yes, we are testers until the game is officially released) and especially how to deal with the black sheeps in your community. Usually you only jump straight to a perma-ban for really grave misuse, and since this is a beta, only something like intentionally messing with the game database and therefore affecting all players (or something along that line) should end in a perma-ban.
So, let's do a quick check:
Did those betatesters something wrong? YES
Did they know it was not right? YES
Was it some kind of hack or bugusing? Apparently NO, pressing B and being able to edit looks, smells, and feels like bad RDMS
Was a reaction warranted? Debatable, thanks to RDMS, but most likely YES
Did messing around with the marketplace elements lead to unintended problems (= orders lost)? YES, but neither could those betatesters have known this nor should messing around have led to these problems. So in reality another bug/problem of the game has been found and will hopefully be fixed.
Did they get some kind of warning for other bad behavior before? NO (as no one got something like that so far)
Does all of the above considered warrant a perma-ban? NO
In my opinion, this was handled in the worst possible manner and I can say that as a consequence, I will leave the game for now after my paid time has run out, as I currently have no more confidence in the game (this topic is just a part of it, but an important part). I have seen a lot of beta tests over the years, I have seen a lot of launches and I am a developer myself (although not a game developer), so I see where all of this is going. I may come back in some months to see if I was wrong, but as it is right now, I don't think I am.