An ITX isn’t the competitor for a Pi. I’d suggest a USFF prebuilt. I use an HP Elitedesk and Dell and Lenovo each have similar tiny PCs. They’re nearly silent or completely silent, and half the size of a Mac Mini. Cost is about $150 for hardware that is more than enough for me, plus they can have 1-2 SSDs and a hard drive inside the case.
Clarification: They're about half the height of the OLD Mac Mini. Better comparison: They're the size of a typical hardcover book if you chopped it to be square.
