The Mi Mix 4 is Xiaomi's latest super-premium non-flexible smartphone. It is also the first of this category to rock an under-display selfie camera. Unfortunately, it now seems this upgrade has helped pushed its repair costs skyward, even compared to the Mi 11 Ultra with its higher-resolution display.
https://www.notebookcheck.net/The-Mi-Mix-4-becomes-the-most-expensive-non-foldable-Xiaomi-phone-to-fix-out-of-warranty.556216.0.html