Although it sports a Qualcomm Snapdragon 845 processor and up to 10 GB of memory, the 6.4-inch Xiaomi Mi Mix 3 launches without facial recognition or an in-display fingerprint reader, and the 5G variant is only supposed to hit the market in the first part of 2019. Nevertheless, this is an interesting device that starts below the US$500 threshold.
https://www.notebookcheck.net/Qualcomm-Snapdragon-845-powered-Xiaomi-Mi-Mix-3-now-official-with-wireless-charging-and-up-to-10-GB-of-memory.346236.0.html