My compromise between pre-built Thin Clients and SBC's was building my own Mini ITX PC. The 17x17cm form factor has just enough connectivity for the size, even PCIe.

The 2018 build came in at ~250$: Asrock J4105-ITX [1] + mini ITX case (with pico power supply included) + 2x4GB DDR4 + 128GB SSD. Runs ClearLinux and works perfectly 5 years later.

The 2024 Mini ITX build will probably feature an Intel N100, like the Asus Prime N100I-D D4-CSM [2] at around 120$ for the board itself, but I'm still looking into options.

[1] https://www.asrock.com/mb/Intel/J4105-ITX/

[2] https://www.asus.com/motherboards-components/motherboards/cs...