Helium
uluqat
It's worth learning from an organization that does the work of preservation of paper on a truly massive scale:
"The 4RU chassis can be fitted with 106 3.5-inch hard drives..."
106 x 29 = 3074 terabytes
2.5 petabytes = 2500 terabytes
3074 - 2500 = 574 terabytes
574 / 29 = 19.79 so about 19 or 20 drives out of the total 106 used for (parity? hot swap?).
I have a feeling that this might be slightly out of my budget.
Online, you aren't getting 6TB+ for under $100 without going used or very sketchy. The best I see at a reputable vendor like B&H Photo is a new 6TB external WD for a Black Friday sale price of $130. Just look at https://shucks.top/, what you want isn't happening.
Watch your local Costco, Best Buy, Walmart stores - you might get lucky if they put out a palette of externals for a special price.
Keep in mind that Black Friday and Cyber Monday just happened.