Does the NAS box really need to cost so much? Three 3tb WD Red's costs about $450, you should be able to get everything else you need for less than that, even accounting for a premium PSU. For example, 12gb is mentioned as being easily more than the last build's 8gb, but did either build actually need that? IMO 1gb of RAM is plenty unless you're determined to run ZFS with de-duplication enabled, though personally I wouldn't. Any decent cheap CPU should be plenty for running ReadyNAS with software RAID which is more than adequate for a solid three-disk RAID-5 set.
Also, I just don't see the benefit of the case; it's huge for what this machine is. If you were loading up on RAM for ZFS then why not go for a case with lots of external bays? A case with enough 5.25" bays can load hot-swappable back-planes, which would be ideal for expanding/repairing always-on storage, and would seem more reasonable for this kind of price point.
I guess I'll just have to try to come up with my own offering for the next best configs result =)