netbsdnoob I was considering buying a workstation (since i generally use laptops) and got interested in these single board computers:
I think you can save your money and prevent waste by buying a used Lenovo/Dell/HP workstation 😉. More chances of finding working components. You may even consider building it yourself, or replace incompatible parts. That' the beauty of tower PC desktops.
Bruno If you want a machine where NetBSD supports all the hardware so the best ones are from 10 years back.
My self-built workstation is from 2017 and with NetBSD 10.0 everything is finally working fine. It wasn't designed with NetBSD in mind (but to run Linux) and had some fresh new or picky components from the very beginning.
The Thinkpad T460 (released in 2018) which I bought used last year and use has a daily driver works amazingly well with NetBSD (graphics, wifi, suspending, webcam, docking station).
10 years or more seems like a too pessimistic time span in my view; I would say that 5-years old stuff will be ok, as long as you look for compatible components (which means checking drivers man pages - 4th section - for the components you want to buy and possibly ask here for confirmation).
Have a look at the BSD Hardware Database: https://bsd-hardware.info/?d=NetBSD