Hi Fee,
As usual I appreciate seeing your opinion on these sorts of things. I'd intended to discuss these sorts of issues more before instating the rule change, but for various reasons which I won't go into here, that ended up being poorly coordinated and an announcement was made prematurely. As such the specifics of the policy change may still change.
The primary reason for the rule change, which I'm sure you can understand, is the fact that we really have no ability to 'force' PayPal or any of the numerous other external payment methods to do refunds or that sort of thing. As has been mentioned, we often run into messy situations where refunds are difficult to impossible because the TC has been spread around so much that recovering all of it is a challenge, to say the least. There have also been some messy cases recently where people have purchased TC from shady sources (i.e. the TC was farmed/hacked/otherwise illegitimate) and we were forced to remove it, much to the buyer's chagrin. As such, the policy change is intended both to relieve us of a responsibility that we sometimes have no way of fulfilling and to teach users to be wary of who they're purchasing from.
I had originally intended to treat external sale scams in a similar fashion to non-/duel scams - that is to say, the scammer would receive a rather hefty ban and the stolen TC (at least, the maximum recoverable amount) would likely be sunk, not refunded. As is obvious, however, it's going to be a bit messy in most any situation and I appreciate your input on the policy change.
I'll ask that we move the discussion of the specifics of the new policy to the MSquad
Policy Discussion thread. As to the original "middle man" suggestion, it seems rather unrealistic to me, expecting a staff member (A high-ranking one, based on the suggestion) to officiate every single TC sale.