The Banana Pi BPI-M7 single board computer is equipped with up to 32GB RAM and 128GB eMMC flash, and features an M.2 2280 socket for one NVMe SSD, three display interfaces (HDMI, USB-C, MIPI DSI), two camera connectors, dual 2.5GbE, WiFi 6 and Bluetooth 5.2, a few USB ports, and a 40-pin GPIO header for expansion.
My brother in christ. A used PC has powersupply, case, storage and cooling. This is about the basic kit you need for a proper pi5 experience. You can very easily hit the 100 dollar mark.
Also, most of the used business PC will have 8G RAM, which would put your little ARM funsies up to the $130 budget range.
And you would still only have 4 shitty cores, no expandability.
And it wouldn’t have gpio, would require at least a square foot of floor/desk space, and it would cost more to run. Price. Size. Gpio. Nobody is running their remote controlled car with a cabled desktop sat on it.
If you just need GPIO for low level electronics there are 20$ SBCs that get the job done. No need for a full RPi5.
Not sure how much more it would cost to run. If you only really talk about stuff a pi can do as well, you wont be maxing out your cores. You will use a bit more maybe. Nothing sort of whatever you only really keep in mind for monero mining.
USFF boxes are quite a bit smaller footprint than 1 sq/ft, about 7"x7"x1.4"
You’re assuming use-case.