I use a 2008 Dell Inspiron laptop as an office PC. I upgraded the CPU, which would be absurd for a new notebook. I also upgraded to 4 GB DDR2, and an SSD. It still works great!
I think it’s always best to keep things maintained and continue using them instead of buying new things. Maybe some of us have a bunch of old stuff laying around. But what stuff are you still using?
I have a case and an 80mm fan from the early 2000s that is my main rig.
Antec Sx1030 I think. It’s been through 4 or 5 CPUs, currently runs a 5800x3d and a 4070.
Did you know some cases have power supplies on the bottom now? I only learned that about a year or two ago.