Is this really that difficult to understand?
If I list a player to sell a for 10K....and lets say his estimate value is 40K-100K....so I list him for 10K, and I get a few bids, and now he is at 17K, and my "brother" bids 18K, and then you bid 19K, and my "brother bids 20K, and you bid 21K and then stops, or keeps going...regardless...the natural outlook would be that if my "brother" didnt get involved in the bidding process you could have had that player for 17K instead of 21K....so now the question becomes did my "brother" really want that player, or was he just bidding it up to help me get more money?
So 2 things have happened by my "brother" making a bid:
1. You had to pay more than you needed to get that player
2. My "brother" helped me to get a few more thousand than I would have
Additionally this would completely rob BB and Transfer list of its integrity. If this could happen then people would always be questioning things, not trusting, and the game itself would become in jeapardy. There are thousands of players for sale at any given moment....can you really not find a comparable player from another team you are not associated with?