I've just been buying old CN62 chromeboxes off of ebay, flashing them for a normal bios and putting Linux on them. I can usually pick them up for around $30 with an intel x86 processor, an M-key PCI-e slot, along with all the low power states, gigabit ethernet, and they're like 3x faster than a Pi 4. They come with 2gb of ram, but it actually is upgradable, so some of the boxes I have laying around have got 8gb in them. No PoE though :(