People take photos as a woman tests out a new iPhone X during a media event at Apple's new headquarters in Cupertino, Calif., on Sept. 12, 2017. (Josh Edelson/Agence France-Presse/Getty Images)

Those already reeling from sticker shock for the new $999 iPhone X got a second surprise Friday: retailer Best Buy is making the phone even more expensive. In fact, it's a whole $100 more expensive.

For those who can't add with their jaws hanging open, that means the iPhone X at Best Buy is now $1,099.99 for the 64 GB model and $1,249 for the 256 GB model.

But the price hike only applies to those who buy their phones outright, rather than those who choose longer installment plans — plans that often end up being more costly for consumers anyway. In this case, though, paying in installments is actually cheaper.

Best Buy said in a statement that the price hike is a consequence of giving people many options for paying for their phones.

“Our prices reflect the fact that no matter a customer’s desired plan or carrier, or whether a customer is on a business or personal plan, they are able to get a phone the way they want at Best Buy,” the company said in a statement. “Our customers have told us they want this flexibility and sometimes that has a cost.” In other words, sometimes you have to pay more to get the phone the way you want.

There can be limits on what sorts of phone customers can buy on their plans — for example, if they have a phone through work. That can prevent them from being able to purchase new phones outright without fees, and Best Buy's price could be reflecting those restrictions.

This isn't the first time Best Buy has applied this premium; in fact, it recently upped the cost of the iPhone 8 and iPhone 8 Plus, also by $100. But given the already high price of the iPhone X, the additional cost for this phone is particularly notable.

Also on Friday, Apple said that the iPhone X sold out of preorders.