[sophacles]

That comparison makes no sense. Your monthly power bill includes taxes, grid connection fees, etc - not just the cost of the power. Depending on where you live, there may also be natural gas bundled with electricity, adding costs that are not relevant to bitcoin. A lot of those fees don't scale with electricity used, but are fixed (driving down the marginal cost, etc).

Further, the rates for your home are not the same as rates in other places (odds are that somewhere else has cheaper electricity than you do).