Flawed purchasing process

I recently made a new purchase directly from Dell, paying with the combination of a previously-earned reward along with my personal credit card.

The process was weird.  At no time during the purchasing process was I given the amount to be charged on my credit card.  Acting on faith, I completed the purchase and was relieved to see the reward was used and my credit card wasn't charged the full amount.

I purchase quite a few things online, and I've always been given a payment breakout _before_ hitting the confirm button.   Why does Dell not provide this?