I don't understand why someone would share a link to a live auction, especially if it is an item they are interested in. To me it seems foolish to get competition on a auction, as I would rather pay less for the item. Only thing I can think of is if they are the seller, or know the seller, they are trying to gouge the buyer, (which is not a gentlemen thing to do in any way shape or form).
That is my understanding as to why B&B does not allow linking to live auctions, and I completely agree to the reasoning, and am thankful for the Mods and others enforcing the TOU of the board.
It is even more nefarious than that... The competition reduction aspect is a side benefit to the membership, but the reason it is in the TOS is to prevent the auction poster from shilling his auction here.
As to why people do it? Many times it is purely innocent... "Is this a good price?" "How much is this worth?" "I bought one just like this for xx.xx, did I get a good deal?" etc....