They don't use 5 time as much power. They use 1.5-2x as much. (13 x 50w ars technica @ 5GH/s vs 600W) https://en.bitcoin.it/wiki/Avalon#Power.
The first batch was $1500 per 66GH/s and they made money off it. The second batch is roughly $8000 but that was an anomalous result because Avalon explicitly said they were building into the cost of the unit the cost of upgrading their production line. If BFL ships, they could conceivably lower their cost back to $1500 and still make money and have a better price point than BFL. Presuming of course they don't have to buy a new factory every time they do a new run.