Who's running 64gb on x79?

Is anyone running 64gb (8x8 or 4x16) DDR3 ram in their x79 motherboard, and did you find a place to get that stockpile of ram cheaply (ideal under $200 USD)

Mobo is an Asus Sabertooth x79, I have a Xeon E5-2667 v2 running in there and 8x4gb sticks of Corsair Vengance DDR3/1600 (two 16gb kits)

I see Corsair has a 8x8 DDR3/1600 kit, but they want a princely sum for it.

There’s plenty of cheap “Dell Workstation” and “Mac Pro” 64gb ddr3 ecc kits on the ebay but I don’t think they’re compatible with x79, I think they’re for the c60?something chipset?

Other thought is maybe sell the x79 + v2 xeon + ddr3 ram and go for an x99 + v3 or v4 xeon + 64g ddr4 ram???