I picked up enough used SAS drives to build an 11 drive RaidZ3 pool. 100 USD each shipped. DIF formatted so had to low level format to native 4k sectors, then run a full run of badblocks, and finally a long smart test to verify no errors. Had a couple bad drives that the seller replaced no questions asked when I provided the smart logs.

SAS controller and backplane opens up a lot of drives that SATA controllers can’t touch.

My old pool drives will be repurposed for a FrigateNVR storage point and a storage point for some other stuff as well as spares for other pools.