We've seen these 3TB drives around $35-$40 before and it was a good deal. Now, available for $25 with quantity:
SUN Oracle 3TB SAS 7.2K 3.5" HDD 7010036 7021037 HUS723030ALS640 NOT FOR PC | eBay
If you don't need the Sun HDD brackets, you can probably sell them off in a bulk deal and recoup some cost, making it < $25 each.
They are 6 yrs old, but if you know HGST, these are very reliable hard drives. I would test them once you get them though.
SUN Oracle 3TB SAS 7.2K 3.5" HDD 7010036 7021037 HUS723030ALS640 NOT FOR PC | eBay
If you don't need the Sun HDD brackets, you can probably sell them off in a bulk deal and recoup some cost, making it < $25 each.
They are 6 yrs old, but if you know HGST, these are very reliable hard drives. I would test them once you get them though.