$189 Hitachi 4TB 7200rpm drives (normally $259-$280)

[etc6849]

http://www.bhphotovideo.com/c/product/835056-REG/Hitachi_0S03355_4TB_SATA3_3_5_INTERNL.html

I've been using two of these and they are whisper quiet. They do cost more than some options, but have a three year warranty and seem to be good drives. I just ordered a few more due to the sale.