cost of a btc has nothing to do with cost to mine it. mining difficulty will naturally seek an equilibrium based on worth of btc. worth of btc is determined by demand for them (increase of supply is set up to remain known) - nothing more, nothing less. not sure why this fallacy is repeated over and over again on these boards.

also not sure how a few days of no fluctuation equals "stability" in a currency that has still increased many times in value over the past 30 days, much less the past year. Give me three months with no more than +-1% per day fluctuations and no greater than +-5% fluctuations overall and we can start talking about price stability.