This seller of used 8 TB 7200 SAS 12G drives has them for ~$109 each. This would be better for an unRAID partity and data drives.
(and there are other sellers too about that price).
This site implied the SAS 2008 chipset controllers do not support 4kn drives. https://bitdeals.tech/blogs/news/4kn-lsi-compatibility-list
A) Can I use this drive with a 2008 controller as is?
B) Can I reformat this drive to 512e (or 512)?
C) if not A) or B), what SAS controller is suggested?
I have a NAS Killer 2.0 now, but as the x5670 CPUs cannot run ESXi 6.7 or 7.0, I will be looking for another NAS Killer option (soon). (Nested within unRAID?)