So little of that is going to happen.

The DDR5 will be registered DIMMs. The GPUs will be 600W paperweights with a custom form factor. Similarly the NICs and other PCI-E accelerators. The motherboards also adopt custom form factors to fit in racks. The hard drives will be using SAS connectors. The flash will be in E1.S form factors.

The server CPUs that you want for a home desktop or small server, high clock SKUs, will be in high demand.

Any savings for someone willing to build a system from second-hand server hardware will be eaten by using adapters or sourcing a rack.

I'm not saying you won't be able to make a slightly outdated frankenserver with more compute than you need, I'm saying that's not going to bring down prices for Grandma's machine that she needs working to check on her retirement account.