Ah now I understand. Thanks for the explanation. I had a friend who you could consider an expert in his collecting field. When a certain person saw him bidding on an item he would often bid straight after him. The consensus was that he was using my friends superior knowledge of “value”. I.E. if he thinks it is good value at $100 it must still be a fair price at $105. At first my friend took it as a compliment but quickly learnt to get friends to bid on his behalf.