So that turns the question into "When is used electric going to be affordable for the average person?" My gut says the answer to that is going to be ~5 years after new electric vehicles are more prevalent. But if electrics continue to retain their value the way the have been it might be a little longer, which is obviously a good thing; a car that last longer has even lower impacts.
You can't expect new cars to trickle down to the used market that quickly.
Used sales are about 2x new car sales [1] and the average used car is probably north of $20,000 [extrapolated from 2]. The best estimate I see of Teslas retaining value is 90% over 3 years [3]. If that holds then it would take 15 years (probably much closer to 10 given inflation, other cars coming up, and the average of other cars going up) for these to hit the used market at an average price point.
Also, the average person doesn't live in California, where the median family income was almost $10,000 higher than the country as a whole [4 and 5].
