I took action on your advice and went for a visit. Pretty interesting I gotta say... some of the transactions are obviously quite large too after browsing some of the listings and recent feedback.

The one question I had to myself was: whats stopping these sellers from signing up as buyers and performing a 'fake buy' to leave themselves more positive feedback? I'm no expert on this, but wont Tor itself will prevent basic security measures other sites may use like logging account IP's etc...