Running 6TB HGST 7200RPM NAS drives in my Drobo5n, I like them a lot but they run very hot. Hotter than the 4TB WD Reds they replaced.
I replaced the Sunon 120mm fan (12v undervolted to ~6.5v stock) with a Noctua 120mm on a 12v rail plus 33ohm resistor, everything is quiet and cool.
EDIT: I see you were referring to 10TB drives, my apologies. Not sure how the HGST 6TB and 10TB compare.
When Amazon was retiring the Quanta LB6Ms from their DC, they were going for dirt cheap ($250-300 a switch). I've got 2 in my home ESXi lab. I was going to post about that as an option, but it looks like the supply has been largely exhausted, as I only see bids in China, and almost nothing in the US under $500