The QuartzPro64 will soon be available with a Rockchip RK3588 SoC, 16 GB of RAM and 64 GB of storage. The single-board computer has plenty of ports too, including dual HDMI outputs. There will be a PCIe 3.0 connection too, but the QuartzPro64 will cost around US$300.
https://www.notebookcheck.net/QuartzPro64-PINE64-announces-a-new-single-board-computer-with-a-powerful-chipset-and-up-to-16-GB-of-RAM.609355.0.html