When I went to one of the special venders in act 2 that you come upon when you are in the world I saw he had a unique yellow item so I tried to shift click it and link it in chat.

What resulted was the item was purchased and then instantly sold back to the vendor. I only realized because my money went down. Upon checking buyback items it was available.

Not sure how/what happened. Didnt want to try and recreate because I would loose 2k+ gold each time.