@threat I have recently been looking at what I can make happen with 8 or so year old xeons, and you can kit out 20c40t (only 2.something GHz base clock though) for not much dosh (~$20 x 2 for cpus, ~$40 for the mobo) if you're trolling through ebay while mercury is in retrograde and the moon is rising.
The temptation to splurge on newer hardware is difficult to resist (or would be if I had limitless cash) but I would be wildly overprovisioning as in your anecdote because realistically, it would just be me plus maybe one or two off and on.