I ran into the same issue a few months back where I hit book and my quote expired. The rates jumped up another $50-60. I kept watching every day until they came back down.
So the moral of the story is : Book a rate that you are comfortable with. You can always go back and re-book then cancel your 1st reservation.
If I were you, I'd check daily, even several times a day. They will probably come back down and you may get lucky with a lower rate.