Used ThinkPads from eBay, especially the smaller models from the X-Series, can make surprisingly cost effective "MiniPCs". If you need multiple devices, as men

Used ThinkPads from eBay, especially the smaller models from the X-Series, can make surprisingly cost effective "MiniPCs". If you need multiple devices, as mentioned in the article, you can even stack the laptops and build a small tower of "MiniPCs" all with different purposes. Another advantage is that they already come with a built-in screen and keyboard allowing for quick debugging, without needing to connect external peripherals.