There are a few places in North America with even lower power costs than that. Under US2c/kWh ($20/MWh) can be found in the Pacific Northwest
Under 3 all costs considered, not under 2.
Might be under 2.5 though if you're on the scale that Gigawatt is building at.
So Canada is even better. :-)
From the tariff's I've looked at, I think the best combination of good infrastructure close to urban areas and low cost is in Ontario & Quebec using interruptible power tariffs. In Ontario large power consumers pay 1-2c/kWh plus a global offset charge of 8-10c in proportion to peak load usage. By shutting down for the 50-100hours per year when the grid is at peak load, you'd avoid the global offset charge. After adding taxes and local distribution, it looks like ~3c/kWh is possible. Peak load in Ontario is during summer heat waves from high A/C use, so shutting down during those times also simplifies HVAC for a mining datacenter.