Selling a new green item - things to watch for

[Izzabo]

Another thing to do is to always have your finger close to Print Screen (and Control + Print Screen in some cases) when trading, so you can get a good screenshot (remeber to show the UI, though ) and later Report those bastards to Arena Net.

Erasculio

LoL GMTA, I always do this and thought I was the only one :)

[Psyringe]

If ANet does not get multiple reports of the same trick and scammer, your chances of getting a refund or the scammer getting banned are pretty slim.

Your method works nice, but if people do it your way, you cannot get scammed at all.

I don't really see this as a disadvantage. ;)

Joking aside, I apologize for misreading your post. I thought you meant "It's difficult to prove a scamming attempt", whereas you actually meant "It's difficult to prove a scam after it happened". Which is true, because in this case you are unlikely to have any screenshots (the chat log would be still available though and might be useful).

That said, as Mawgleah has already pointed out, ANet supposedly keeps logs of chats and trade sessions and is probably able to identify scams if you can give them basic information like IGN, date, time, and place. You won't get a refund though, nor will you get any confirmation that any action has been taken.