If miners have the same power consumption and difficulty as today and you think mining cost floors the price then the price has to be 8 times higher than it is today for miners to break even. Which is circa $50k.
They won't. The market price of Bitcoin determines the network difficulty. If the price goes up then it is profitable to mine so more people will mine resulting in the difficulty going up. If the price goes down the miners with the highest costs become unprofitable and they will stop mining resulting in the difficulty falling.