There's this $10 board on Aliexpress called Milk-V Duo S. It's been popping up on my recs every now and then. Looks interesting.

https://aliexpress.com/w/wholesale-Milk%2525252dV-Duo-S.html

Taken directly from its description:

>Milk-V Duo S is an upgraded model of Duo with an upgraded SG2000 master with a larger 512MB RAM and extended IO capability

>Onboard WI-FI6/BT5(Model Milk-V-Duo-S-512M-Basic/Milk-V-Duo-S-512M-eMMC does not have this function)

>USB 2.0 HOST port

>100 Mbps Ethernet Portwith PoE Support (via PoE HAT)

>Dual MIPI CSI with ISP

>The device also supports switch between RISC-V and ARM boot via a switch