I've said it before. An extended bid auction can have several strategies. However, bidding $1 more than the other guy is seldom the right one. This is proxy bidding, and all you accomplish is to raise both your and the other guy's blood pressure.
My strategy is and always has been to bid the highest price where I won't feel bad about losing the item if I'm outbid. I generally place this last bid in the last hour before closing, AND THEN TURN OFF THE BROWSER. People are always inching up the bid, and I can't stop them, but I think in some cases constantly being automatically overbid by my proxy causes some to drop out earlier than they might have if we were trading high bids in extended bidding.
In large auctions with staggered closing times, I will come back halfway through and maker a budget decision whether to raise my bid on later items, but I still don't wait for the hammer time. I either won or I didn't.
Yeah, I lose some, but I never wake up the next day with buyers regret. I also take the results to heart for future bids. If I bid $100 on poster X and it eventually went for $200, I know I'm going to need to decide if it is worth $250 to me and bid that the next time. And heck, I sometimes win something I bid $150 on for $30. Good feeling there.
There are very few items out there that are once in a lifetime opportunities.