Ebay Cheating

Is there a way for a seller to know what your maximum bid is and get a friend to bid you up to your limit but not over?

I bid on an item where the seller was selling the same item in more that 1 auction. At the last minute, someone swooped in and bid just enough to push me to my maximum bid but not over, so I still 'won' but I paid the max. This other bidder could have bid on other auctions for the same item (which had no bids) but he bid on mine and pushed me to my max.

I wonder now if this other buyer was a straw working with the seller to make sure the item didn't sell for the initial low introductory price.