Guys, what would be a Supermicro case that would NOT cost an arm and a leg ...
https://www.ebay.com/itm/SuperMicro...hash=item58fb7b8da8:m:m6aIBf28d6jFDcumA416Lwg
$155 more (shipped) more than the Norco case you're looking at. Doesn't have drive trays but you can get them for $2/ea in quantity, so call it $40 for all the bays. Screws are practically free, but lets call it $5 which puts you at $200 more than the Norco which sounds like a lot at first. But it includes a pair of 920w
Platinum rated power supplies ($200/ea new, $100/ea used). $200 would get you a crappy, refurbished, lower wattage redundant standard ATX setup at best.
So, yeah, it's used. But for about the same cash you're getting a drastically nicer case, and drastically better power supplies. Oh and a backplane that you don't have to worry about blowing up if you look at it wrong. It is worth mentioning it's a direct connect backplane like the Norco, meaning you need 6x 4 lane connections to feed all the drive bays. For that reason, I'd probably recommend spending another $100 to get this case:
https://www.ebay.com/itm/SuperMicro...252716&hash=item5907c757be:g:QCEAAOSwUd9aheya
Same case and power supplies, plus has the drive trays and screws so that drops the price difference to about $50 over the other Supermicro. This gets you a newer backplane and more importantly it's an expander which means you only need a single port to feed it instead of six ports.
Given you asked what the back plane is, I also feel like I should point out a couple of items.
1) You will need SAS HBA's or SAS RAID controllers to use with these. SATA cards won't work.
2) With either of the direct connect back plane options, you will need either 3x dual port HBA/RAID cards or 2x quad port cards. That's at least $140 in RAID cards (if buying used), plus cables, plus using 2-3 PCIe slots.
3) It would probably be helpful if you give us more details about your end goal so we can give you other tips.