Bitcoin price is independent from mining difficulty. Price won't go up just because more miners are hashing. Instead, miners are leaving / joining the network depending on BTC price and how profitable it is for them if they can pay their running costs from their mined Bitcoins. At a higher BTC price more miners will be able to join, if the price gets lower miners are leaving the network and stop mining.
Average cost for mining a BTC will normally always be a little bit below the Bitcoin price that miners will make at least a decent profit after expenses (maintenance / electricity), otherwise there is no need for them to do mining. And there won't be any miners mining at a loss obviously.
Keep in mind that the hardware has also a price to purchase and a limited lifetime. These costs need also to be covered if the miners won't end at a loss. Makes no sense for miners to get a profit of around 1 percent per month when the lifetime of the miners is only around 2 years.
