In case anyone is wondering, here's what my current build plans look like. I still need to buy fans and some Molex to fan 4pin power cables, but I'm holding off on those until I get the case.

Fractal 804 case ($142.91) https://www.amazon.com/gp/product/B00K6OVG0I

(10) Seagate Exos 14 TB drive ($2090) https://www.amazon.com/gp/product/B07T63FDJQ

Intel RAID Expander Card (RES2SV240) ($155) https://www.amazon.com/dp/B0042NLUVE

Power Supply ($94.50) https://www.amazon.com/gp/product/B08PDV45F8

(3) Mini SAS to SATA Cable ($41.97) https://www.amazon.com/gp/product/B012BPLYJC

Sata power cable splitters ($6.99) https://www.amazon.com/gp/product/B07T356R21

Sata 90^o angle adapter ($6) https://www.amazon.com/gp/product/B07P5N714P

Total cost: $2442.87