I bought a CN62 Chromebox, and put MrChromebox's Bios on it -- I did the rounds comparing it with a Pi 4 and it was 2.5x faster, and could easily saturate my gigabit connection. It came with 16gb of storage, and 2gb of ram; but using ACTUAL DRAM slots. I could upgrade it to 16gb if I needed to down the line.
The whole thing, cost me like $45 shipped; power supply, storage, everything needed...and it's an X86 instruction set - so I can use whatever version of Linux I want, without any crazy Raspberry Pi specific patches/builds.