The base tier of Lenovo's Tiny line for 8th and 9th generation Intel, in a chassis under a liter that idles around 8 watts. One M.2 NVMe slot, an i219-V network controller, and a PCIe riser slot that accepts a low profile card, which is how people add 10GbE. That riser is the reason this family beats the Dell Micro and HP Mini equivalents, neither of which has a PCIe slot at all.
Across 120 listings tracked in the last three days, the median total cost in USD including shipping is $175, and the lowest is $75. RackSniper flags a listing once it falls at or below 70 percent of the trailing 30 day median, which for this product means roughly $122 or less. Condition and configuration vary widely on used enterprise hardware, so treat the median as a reference point rather than a target.