Thanks for asking... it's a common question.  At the time of your order, our system authorizes your credit card.  Authorizing means your bank has told us that your card is valid and places a hold on your card for that amount.  Note that "authorizing" is not the same as "charging."  Your card has not yet been charged.

When the feature ends each weekday at noon EST, the final price is sent to your bank and we capture the funds for that amount.  Now your card has been charged... and you got the day's lowest price!

You will never be charged more than the authorized amount.  And if the price drops between when you order and when the feature ends, you'll be charged less than the authorized amount.  So spread the word!