The VPS power bill is already paid with its price. For the Raspberry you have to pay the power bill.

Here in Germany we now reach 40 Euro Cents/kWh. 5 Watts 24/7 are 17.52 Euro/Year 10 Watts 24/7 are 35.04 Euro/Year. The Raspberry is somewhere between.

That is the reason why I replaced my Dell t30 Server with two Contabo VPS servers. I also don't have to worry about my ISP screwing up my connection.

* As someone else said, overclocking helped, and I had a reasonable passive cooling case to help there.

* I used Paper instead of the normal Minecraft server, and I ended up spending a decent amount of time optimising the configuration. Paper by default comes with a bunch of optimisations, I enabled some more, although I also disabled some that were interfering with the more technical areas of Minecraft that I enjoy more.

* Whenever things started lagging, I went on a killing spree for our main farms, and that tended to work well enough. Most of our contraptions were turned off by default, or designed not to be too laggy. I also restarted the server every night, which worked reasonably well as a sort of ultimate GC.

If I were going to do it again more seriously, I'd probably get a cheap mini PC and use that instead, but for what it was - me and a friend rediscovering Minecraft after having not played it probably in about 5-10 years - the pi4 held up pretty damn well.