I've bought a lot of great stuff on eBay....my strategy is to open two windows to the main item page....on one of them click the "Bid" button and input my bottom-line bid. Submit the bid, but do NOT confirm (last step) yet. Keep refreshing the first page until you are as close as you dare (I take it down to 5 seconds, but YMMV). Switch back and click the confirm button to submit the bid.

I rarely bid on expensive "must-have" items, more casual ones, so I'm not as concerned if I cut it too close - that's part of the fun! Best day for me was getting the bid in with one second to spare and winning the item by one penny

Bruce