True. I wasn't arguing for 700W with single card, but felt that 300W sustained might be a bit optimistic if one is aiming for $500 of Bitcoin revenue per month. The OP was offering a conservative estimate, and one could just as well point out that 20 cents/kWhr is also on the high side.

I was just using the layout my tech guy at the comp lab told me, and he was talking about using two gpus.