NanoPi NEO is an $8 Ubuntu board

https://www.electronics-lab.com/nanopi-neo-8-ubuntu-board/

The NanoPi NEO is another fun board developed by FriendlyARM for makers, hobbyists and fans and costs $8. It is based on Allwinner H3, Quad-core Cortex-A7 Up to 1.2GHz and comes with DDR3 RAM: 256MB/512MB versions and USB and Ethernet connectivity. NanoPi NEO is an $8 Ubuntu board – [Link]