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 an old heatsink for an i486 that now cools the chipset in my NAS motherboard. Bought a used board for parts originally just to find out it literally only needed heatsinks and a new CPU power connector.