antdude I don’t think we have much of a choice, we have to use / reuse old parts.
Fortunately for me, I had a habit of just buying PC hardware in anticipation of using it or if it looked like a good deal. I didn’t just buy because I needed it at the time. I’d get things like an extra ATX case, HDD’s, SSD’s, PSU’s etc. RAM is the exception as this was bought on an as needed bases.
Still, if I wanted to build a new system now all I would need is the new motherboard and CPU. For RAM I could either pull a 16GB DDR5 DIMM from my RyZen 9 7950X build (which has 2x) or I could pull an 8GB DDR5 SODIMM from my UGreen DXP8800 Plus NAS (which has 2x) and use a SODIMM to DIMM adapter.
I wouldn’t buy RAM at these prices if it could be helped. Maybe a bundle deal if it were economical enough.
Tough times mean you have to do what you have to do.