With the iPhone XR available starting this Friday, Apple has updated their iPhone Service Pricing page to reflect the latest iPhone on the market. The schedule lists the repair costs for an iPhone XR without AppleCare+.
For screen repairs, the cost is $199. That is substantially less than the cost of the iPhone XS ($279) and iPhone XS Max ($329) but should be given that the XR uses a LED display versus the more expensive OLED display of the XS lineup.
For other damage to the XR, such as breaking the back glass, the cost of a repair is $399. This too is far less than similar repairs on the iPhone XS and XS Max. Those repairs start at $549 and $599 respectively.
Of course, all of this can be avoided with AppleCare+. If you purchase the extended warranty and damage coverage option from Apple, you will only pay $99 for damage to your XR. You can do that twice under the program. A screen repair is $29 with AppleCare+. For a point of reference, AppleCare+ is $149 for the iPhone XR. You can purchase AppleCare+ on your iPhone XR (or any iPhone or iPad) up to 30 days after purchase.
To get the full breakdown of costs on iPhone repairs, head over to the Service Pricing page.