SAS2 what? I'm assuming you mean backplane. Is it a TQ? A single channel expander? The dual expander?
If it's not an SAS2-846EL1/2 card, and that's what you're after...to me it doesn't sound like a great deal, more like a normal one, not even a regular sale maybe.
CSE-846TQ-R900B is on there for $200. Some with and some without motherboard/cpu/ram. They aren't probably the 920 power supplies, but at that price, you could buy some, sell the 900's(or keep as spares) and you have what you listed above on a TQ backplane for still less money.
So to me, without knowing what backplane, it doesn't sound like a great deal.