I spend enough to pay for electricity, which is about $65 a month for my 900 MH/s.
What % of your BTC income would you guess that is?
Today, at $11?
900 MH/s gives me approx 14 BTC a month. $65 at $11/BTC = 5.9 BTC = 42%
However, my next bill is not due for a few weeks yet, and I hope to get a better price than $11.
For example, if I am able to sell at $14, it would be 33%