If you need a 2U expansion that holds 12 hot-swap 3.5" drives, see eBay item 220778792156. It's a Supermicro server chassis model SC826TQ-R800LPB with 12 bays and one 800 watt power supply for $175 - which is very cheap. The seller has "more than 10" available.
The case is fairly deep so check your rack depth before buying. Also note that the backplane is 12 SATA connectors, not the more useful SFF-8087 connectors.
To convert this into a nice JBOD, you need a $40 Supermicro CSE-PTJBOD-CB2. This is a small board that connects to the power supply and puts out MOLEX connectors to power the drives and fan connectors to power the fans - plus a connector that enables the front power switch on the case to turn on and off the whole system.
At that point you have 12 SATA connectors ready for your use - though you'll need long cables. If you have the budget, you can add an Intel or HP SAS expander card, pay $310 to switch to a SAS2/SATA3 expander backplane (part number BPN-SAS2-826EL1), or expose the drives as 3 SFF 8088 connectors out the back of the chassis - though any of these options will dramatically increase the budget. When buying "cheap" used storage gear, it's often the "extras" that cost the most!
The case is fairly deep so check your rack depth before buying. Also note that the backplane is 12 SATA connectors, not the more useful SFF-8087 connectors.
To convert this into a nice JBOD, you need a $40 Supermicro CSE-PTJBOD-CB2. This is a small board that connects to the power supply and puts out MOLEX connectors to power the drives and fan connectors to power the fans - plus a connector that enables the front power switch on the case to turn on and off the whole system.
At that point you have 12 SATA connectors ready for your use - though you'll need long cables. If you have the budget, you can add an Intel or HP SAS expander card, pay $310 to switch to a SAS2/SATA3 expander backplane (part number BPN-SAS2-826EL1), or expose the drives as 3 SFF 8088 connectors out the back of the chassis - though any of these options will dramatically increase the budget. When buying "cheap" used storage gear, it's often the "extras" that cost the most!