You're leaving yourself wide open to having someone (not the seller) run you up just for the fun of it. Anyone can see that you've got 11 bids above the current top bid and they can safely put a few bids in without any fear of becoming the top bidder. You might scare the odd other bidder off but they're more likely to be tempted to have a bit of fun and run you up out of spite.

The zero feedback bidder is behaving exactly how you'd expect a newbie to, but with your feedback you should know better by now.