I think the N100 type CPUs are limited on PCIe lanes. You end up with less nvme, less sata, and usually no slots.
You can find x570 am4 boards for less than $100 now. Two nvme, 8 sata, 2 big slots and 2 small.
But all of that flexibility and expandability is going to cost you in power. My 7700x w/A380, 3 hdd is 125 watts 24/7. $10 a month on my power bill. I think those n100 mini PCs only have a 35w brick and idle at less than 15w.
https://pcpartpicker.com/list/yqX3C8
$650 for the box leaves you $350 for drives and a 10Gb NIC. I’ve been using serverpartdeals refub drives with good results. They’re ~$10/tb.