Xiaomi has introduced the Mi Box 4S Pro, its latest Android TV box. The device can output in up to 8K for just CNY 399 (~US$60), meaning that it supports HDMI 2.1. The Mi Box 4S Pro also has 2 GB of RAM and 16 GB of storage.
https://www.notebookcheck.net/Mi-Box-4S-Pro-Xiaomi-announces-8K-Android-TV-Box-with-HDMI-2-1-for-US-60.502362.0.html