My storage set up:
1x 256GB NVMe for my OS and important applications
3x 400GB SSD in Raid 0 for game installations and rest of applications
1x 2TB SSD for video editing and game saves
1x 3TB HDD for my old long term storage, I've filled this so I added recently:
1x 4TB HDD for my current long term storage, I've got awhile to go to fill this but when I do, I have another 4TB HDD on my desk I can install. I also have an older 2TB HDD filled of cold storage in my basement.
I mentioned before I have access to SSD/HDDs at work so the 4TB I grabbed from an old storage unit we decommissioned and had a few spares we won't use again. The 400GB SSDs are like candy at work, probably have over 100 of them that we don't use anymore as we use 480GB SSDs now. And the 2TB SSD was a test SSD, we had a period when we tested out like 10 different SSDs and brands to see which one to purchase in mass quantities and well, we didn't go with these so they had no use besides in my PC now.