When you buy from e-bay and you really want the item, you have to sit and watch it until the last minute of the auction. Someone else may be doing the same thing, but at least have up to the last second to make your mind up how bad you want it.
Look for when the auction expires. Make sure you're registered. Be on the computer and ready as the clock ticks down in case you're out bid. This is how you minimize your cost. When bidding, consider that the alternative may be the $900 one.