I agree that for transportation, there is a long way to go before fossil fuels are displaced as the dominant source of energy. But the cars are already affordable, it's just production scale that's lacking. The Tesla Model 3 is beginning production (this week I believe), and Chevy has the Bolt, which is similarly priced in the $35,000 range and has a slightly better range. As for batteries, Tesla has the Giga Factory which is currently only operating at a fraction of capacity. When it is at 100% capacity, that single factory will be producing more lithium ion batteries than the rest of the world combined. They built that factory because they forecast that demand. The question is how quickly the demand will materialize.
$35,000 for the Model 3 is still a bit high for me. But I have heard that there are additional expenses as well. For the Model S, the battery needs to be replaced every seven or eight years, and this is going to cost you a fortune. Eight years is not a very short duration. But when your Tesla Model S 70 costs around $80,000, you may be expecting it to last at least ten years.