I think the price will stabilize at the cost of electricity for mining at the current difficulty level, multiplied by some markup to pay for hardware and time, say 20%-50%. Miners located in areas with cheap electricity will have an advantage.
Bitcoins are like any other commodity, with both supply and demand. Few miners will sell at a loss, and those that do will quickly leave the market, leaving miners that price their bitcoins at an acceptable profit range, where it's still worth participating in the market.
I've seen various calculations that cost of electricity is around $1.50/bitcoin at a recent difficulty level, so I think with a few more increases in difficulty, bitcoin will be somewhere in the $5 range. The 1000% markup that was happening at the $17 level just can't last.
This idea has been brought up and rejected many times. The cost of electricity is a moving target. If miners leave, difficulty drops. If miners come, difficulty increases. This is not a fundamental.
There is some weak influence, as current miners might not be inclined to sell for less than their costs, but there is more influence the other way- miners look at the profitability and decide whether to mine or not, which tends to drive total btc costs up or down toward a suitable value.
There are a ton of market factors, but ultimately if, say, $1B of goods are being traded with btc, then a minimum of $1B worth of btc must be purchased to support the market. Nobody buying btc to use as currency cares what the value is, as the bitcoin is divisible. e.g., if Bob wants to send $100USD to Amsterdam, Bob will buy $100USD worth of bitcoin, regardless of how many bitcoins he receives.
The total market required for day to day exchanges is an absolute minimum value of the bitcoin. This is obviously only one factor in the bitcoin value, but it is a clear counter example to your claim.
