My answer is a swift & painful drop to zero.
In a MarketWatch column, I wrote last May-June, I thought what it would take for bitcoin to become worthless. Bitcoin is getting close to that point. once Bitcoins price falls below its cost of mining, the incentive to mine will deteriorate, thrusting bitcoin into a death spiral. Because the ledger that maintains the records of who owns what bitcoin is, after all, a set of encrypted numbers that cannot establish the ownership of anything bitcoin will become worthless.
You are right. if the cost of producing bitcoin (mining) is higher then bitcoin price then it's obvious that the Bitcoin will become worthless if it continues like that. But the question is why people are selling bitcoin for less price then ? I mean the miners and traders are the ones who decide the price. then why don't they increase the price higher than the mining costs ?
2nd thing is there is always a solution, right now it seems bitcoin will become worthless but maybe developers figure it out somehow. with better and cheap mining equipment.