Most ryzen motherboards support 128GB ram and they cost as low as $50
And DDR memory is free, of course 
As I said, 128GB not-fancy DDR4 is $500, not $3000
Or maybe even lot cheaper, just not sure how safe this is:
https://ddramdisk.store/shop/
but it should work in your motherboard, despite 32gb restriction
It is not RAM. The description says: "RAM disk, this is a “SSD” disk based on RAM memory chips. This kind of disk has an exceptionally high read/write speed and an unlimited lifespan. To the operating system the RAM disk is indistinguishable from an SSD or HDD disk and no special drivers or setup is required."