At this point, you're more likely to find an off-lease laptop running Linux. Bonus - for roughly the same price (assuming you buy a MicroSD card, power supply, case, etc), you'll get a screen/keyboard/trackpad, battery backup, a lot more performance, and a real SSD. There's nothing here that can't be done with any bog-standard Linux host.
As we learned in Europe in 2022, electricity isn't some infinite resource. When it gets rationed, the price goes way up.
A raspberry Pi costs up to 1€/month in electricity to keep running as a server, while any used computer will cost quite a bit more. When suggesting old hardware for server use, make sure to consider the total cost, not just the cost of the hardware itself.
It isnt 2005 anymore. Old hardware nowadays is "Lot of 5 LENOVO THINKPAD YOGA 260 i3-6100U 4GB Ram 128GB SSD Cracked Screens" coming down to $40 a pop. 2x TDP (15W vs 7.5 of rpi4) but at the same time >2x CPU power, >10x GPU power. Not to mention you get real SATA SSD storage, real DDR4 sodimm slot, keyboard, and battery backup.