Father, Hacker (Information Security Professional), Open Source Software Developer, Inventor, and 3D printing enthusiast.
6TB WD Black (7200RPM spinning rust) is ~$130 https://www.amazon.com/gp/product/B09NCMMSQX/ whereas a 4TB SSD is ~$150: https://www.amazon.com/Silicon-Power-Performance-Internal-SP004TBSS3A55S25/dp/B0BVLRFFWQ/
So you get slightly better bang for your buck with spinning rust but not much.
OMG great question! I want: