Comment by zozbot234

If you don't need the full memory bandwidth of DDR5 for any particular application area, the best solution is probably just to add flash storage for mostly read-only data and Intel Optane (still sold in the secondary market at around $1/GB) for write-heavy scratchpad space. The latter gives you around DDR3ish performance at a higher power draw than DRAM or modern flash, but its wearout-resistance and lower latency compared to flash still matters.

> Quotes came back to about €200k for 48 x 96GB DDR5-5600 RDIMMs.

That's around EUR 40 per GB? That seems quite high compared to what consumer DDR5 RAM is selling for, though it being RDIMM may account for some of the difference.