I did not realize you could buy QQs at the stores throughout the park AND at the online price! I totally agree with 919Florida to wait until you are at the park to decide. And get there when the park opens!
We bought the QQs for our visit the week of Christmas. We knew it might be crowded, we had a very full day planned with the extra shows, and we knew we would want to do multiple rides on Manta, Kraken, and Journey to Atlantis. (And, honestly, I just really hate waiting in lines!) We did not regret our decision.