Have you ever studied the history of industrial civilization ???
Pretty much EVERY new type of technology first comes to the market as a rich man's toy. As scale goes up, manufacturing investment pays off, processes get streamlined, you know, boring industrial engineering / economics things, price comes down.
Before the Ford Model T all cars were rich people's toys.
Then big cars were only affordable to the rich.
Then hybrids were only affordable to the upper middle class.
Although the fully loaded Tesla Model S is still very expensive, there is a 100% difference between the most basic and the top of the line Model S.
In 10-15 years I expect a Tesla Model S / X to sell for US$ 50k corrected for inflation.
The most expensive component is the battery pack, Li Ion prices will drop by half over a decade.
The other big ticket item is the electric motor, once Tesla is buying a million a yr (vs current less than 100k / yr) prices will drop substantially too.
And the more modest Tesla Model III should go for US$ 40k before incentives in 2018/2019. Should be a much better car than the Nissan LEAF, better performance, better range, at the same price.