You can also go on eBay and look for older mini PCs. I got an HP Elite desk Mini G5 for like $70. Didn’t come with storage (usually the case), but an NVME/2.5 SATA drive is cheap.

It has an Intel 9500T and 16GB DDR4 RAM. The N series chips are more efficient (I have one of those N100 mini PCs, too), but the full chips offer more power (if you need it). Of course both of them will be significantly lower in power usage to an old desktop/server, by far.