http://www.amazon.com/NETGEAR-ReadyNAS- ... s=readynas
I am looking to upgrade to a 6 bay and thought I would give you folks a shot at my 4 bay ReadyNAS 314 Diskless. Its truly more than I can handle and I haven't used 1/4 of the features. It would be perfect for a small business application and if you are willing to spring for 6 TB drives that's a total of 24 TBs in storage. WD Red 4 TB drives are currently $150 a piece. This box will allow you to hotswap or add drives if you can't fill all 4 bays at once. I've had this box for a little over a year with no issues.
I'd be willing to let this go to a good home for far less than I would charge on Craigslist. If you have a serious inquiry send me a PM.