Pre-orders have come and gone, as Apple has since updated its website with non-warranty service pricing for the iPhone X. You may want to keep this one in pristine condition, seeing as it will cost you a flat rate of $279 USD for screen repairs for the iPhone X.
In addition, Apple is charging $549 USD for all other iPhone X fixes, unless the damage is covered by Apple's standard one-year limited warranty.
You can, however, purchase Apple Care for the X. This will run you $199 USD up front (in the U.S.). With Apple Care, screen repairs are $29 USD and other damages, $99 USD, albeit you are limited to two incidences.
See below for the pricing breakdown for iPhone X fixes.
Australia: $419 for screen repairs, $819 for other damage Canada: $359 for screen repairs, $709 for other damage Germany: €321 for screen repairs, and €611 for other damage United Kingdom: £286 for screen repairs, £556 for other damage United States: $279 for screen repairs, $549 for other damage