[pclmulqdq]

Economies of scale in storage are significant. Also, I don't know why you put up with your university charging 100x that when you can store things on AWS for $5-10/TB/month (or less). That comes with all the guarantees (or more) of durability and availability you get from the university.

[lnauta]

Don't forget bandwidth costs at this scale are significant to say the least.

[pclmulqdq]

I assume most of that exabyte is stored in 2-3 datacenters, in which case the bandwidth cost is actually relatively small. Downloading it would cost a fortune (or take an eternity), but if it stays in the datacenter (or stays in AWS), bandwidth is cheap.