The Banana Pi BPI-M4 is a mouthful, but it packs a punch thanks to its quad-core Realtek RTD1395 SoC with ARM Mali-470 MP4 graphics, 1 GB of DDR4 RAM and 8 GB of eMMC flash storage. The developer board is a dead ringer for the Raspberry Pi 3B+ and is compatible with most HATs too. The Banana Pi BPI-M4 currently ships worldwide from AliExpress for US$35.
https://www.notebookcheck.net/Banana-Pi-BPI-M4-a-Raspberry-Pi-clone-that-packs-a-more-powerful-SoC-and-costs-just-US-35.423926.0.html