Congrats on the 1 center. I've been pleasantly surprised a few times when lowering a bid to 1 cent actually doesn't change anything - except for what I pay for it.
Bid optimization for top position keywords is something people often forget about with Google. Try it with some other high ctr ads also. If you say you're willing to pay more for a kw where you're already top position they'll gladly take it - test it until you find your sweet spot.