It's not arbitrage because of the labor spent looking through ebay listings and dealing with surprises (broken hardware, incorrect listings etc.)
Also the machines have to go somewhere and that costs a lot because if someone can do it cheaper they'll just sell VPSs for cheaper than you can host them. Doing it cheaper means more compute per rack/watt which means newer hardware.
Also the machines have to go somewhere and that costs a lot because if someone can do it cheaper they'll just sell VPSs for cheaper than you can host them. Doing it cheaper means more compute per rack/watt which means newer hardware.