If its something I really want the best strategy I've found is to wait till the auction is almost over and then open 2 brower windows. Set one to the auction itself and set the other one up as if you are bidding to the maximum you are prepared to bid but dont hit confirm till you have about 10 seconds left on the clock.
Bidding you maximum early on can drive the price up as people will see if you are prepared to bid less than you oeverall.