the NUC is a bad example. Plenty of used mini-PCs in secondary markets that can be had for sub-$100-150 price range with 7th-8th gen i5 or i7 CPUs. More I/O options than a raspberry Pi and beats a Raspberry Pi many many times over in performance. Including onboard media transcoding via QuickSync. By the time you add a power supply, SD card or add-on board for a nvme m.2 drive the price of the Raspberry Pi is going to be same as what a mini-PC with more hardware options and performance is going to cost.
Regarding lack of GPIO - if you're going to use it for a server, then not sure why GPIO is even needed. But if you need GPIO for hardware interfacing, then plenty of much cheaper boards out there than the raspberry Pi. Such as the dozens of different types of ESP32 boards.
As for power draw - yes, a mini-pc will definitely draw more power. I guess it depends on electricity cost at your specific location. I'm currently running about 25 containers on a HP elitedesk G2 with a Intel i5. On average it draws about 15-20 watts. It can go high as 40 watts when I'm streaming something from Jellyfin that requires real-time transcoding.
As I said above, used is not an option for anything other than a hobby. You found a great used PC for $100. Awesome, now get me 50 more of those with the same specs and price. And don’t forget to make sure every power supply, RAM and SSD is working properly.
I have a used m75q running 16 full blown windows server vms and a few Linux servers and it draws about 35w and cost me $200 all in with 2tb of m.2 and 64gb of DDR4 ram and it's still got room to grow.
I also ran a data center and an MSP where we always sourced used servers and never had issues with them running for longer than their intended 4 to 5 year lifespan.
I have pretty heavy workloads I run for side projects for friends and run everything on 3com gig switches I also got used. HP still warranties them and releases firmware.
Schools use off lease hardware other than chrome books that get beaten to death by kids without problems for years.
I really fail to see your argument against used hardware.
The pi ecosystem has become a total accessory one where you need non standard power supplies and video adapters to connect them up where a single used desktop PC gives more value and less points of failure - and when things do fail you can find readily available off the shelf parts to fix them.
You need 50 of those to run at home for selfhosting/homelab? I've bought a few. Never had any issues. They're not hard to find if you need them in bulk. But then again, most people don't need 50 of them or even more than a few for home use. Amazon renewed sells mini-PCs and you can just as easily return them if there are issues. If you need 50 of them, then your use case is for enterprise or business use. You should probably not look at a raspberry pi then either.
Even if you don't want to buy on secondary market because concerns around ram, power supply or SSD. Then even a new mini-PC running something like a Intel N100 for $100-150 will vastly outperform a Raspberry Pi 5- yet still provide better I/O options + QuickSync.
Yeah I didn't mean a NUC from Intel (who have just stopped making them anyway). I meant the Beelink kind of mini-PC or indeed some used systems which is exactly what I use, and generalised them under the term NUC. That was not very clear.
Regarding lack of GPIO - if you're going to use it for a server, then not sure why GPIO is even needed. But if you need GPIO for hardware interfacing, then plenty of much cheaper boards out there than the raspberry Pi. Such as the dozens of different types of ESP32 boards.
As for power draw - yes, a mini-pc will definitely draw more power. I guess it depends on electricity cost at your specific location. I'm currently running about 25 containers on a HP elitedesk G2 with a Intel i5. On average it draws about 15-20 watts. It can go high as 40 watts when I'm streaming something from Jellyfin that requires real-time transcoding.