The Argon ONE M.2 brings native M.2 SSD support to the Raspberry Pi 4, along with full-sized HDMI ports and a software-controlled fan. The useful features from the Argon ONE remain too, including its stylish design. The Argon ONE M.2 is available for US$45.
https://www.notebookcheck.net/Raspberry-Pi-Bring-M-2-SSDs-full-sized-HDMI-ports-and-active-cooling-to-the-popular-single-board-computer-with-the-Argon-ONE-M-2.497598.0.html