Based on my personal experience used server with 2x e5 2650 2ghz 8 core CPUs and 8x 4Gb Ddr3 1333mhz sticks without raid card and HDDs comes for 130€ without VAT in Europe. It gives 5210hs on RandomX while taking 278W of power.
Based on market prices, published benchmarks and personal research PC with AMD TR 1950X with cheapest MB, 2x cheapest ddr4s, cheapest 550W gold rated PSU and “normal” case comes for 845€ without VAT in Europe. It gives ~ 8000hs and takes (or should take as it’s tdp is 180w compared to 190w on 2x e5 2650) ~ 260W
Let’s assume we pay 0.1€ per kWh
It comes 1kh used RandomX system comes for 24.95€ and takes 53.35W.
In a 2 years mining perspective we’ll pay 118.5€ to get 1kh/s on RandomX using used stuff.
1kh new RandomX system comes for ~105€ and takes ~32.5W.
In a 2 years mining perspective we’ll pay ~162€ to get 1kh/s on RandomX using new stuff.
So.. if you can find a good used server deals and you can deal with a noise – it’s the best bang for a buck atm.
I’ll appreciate if someone will correct me and provide correct tr 1950x or other ryzen hashrate and consumption.