You could technically do that from like 2x ~$150 used business desktop PCs off ebay, 10th gen Intel CPU models or around there with Core i3/i5 CPUs.
Throw some M.2 SSDs in each one in a mirror array for storage, add a bit of additional RAM if needed and a 10G NIC. Would probably use about 30-40W total for both of them.
Minecraft servers are easy to run, they don't need much especially on a fairly modern CPU with high single thread performance, and only use maybe 6GB of RAM for a modded one.
You're not asking for a whole lot out of the hardware, so you could do it cheap if you wanted to.