>>105697421 (OP)RAM in these old PCs can either be really cheap if they were mass produced like the Optiplex's, or they can be really expensive if they're some sort of esoteric build. I snagged a SFF Optiplex 7090 for pennies with a 512 GB NVME drive inside, 7th Gen Intel and 32 GB RAM.. I slapped a 2 TB HDD in there, and now it runs my Proxmox Hypervisor. You can get really creative with these old machines, and they don't suck a lot of juice.
The 'tiny' version of these are where it's really at. You can fit them almost anywhere. I bought a bunch of tiny 5070s off ebay, and tested out some Hyper-V clusters, PRoxmox cluster.. One is segmented off my home network as a P2P device with an external HDD connected via SATA.
Just don't be a retarded nigger and you can find solutions.