Source: Tesla Motors
quote: The Model S comes in three different versions, with 40 kWh, 60 kWh or 85 kWh battery packs. The lower-end 40 kWh base model will sell for $57,400 while the higher-end model will sell for $105,400.
quote: Car with 40kWh battery costs $57k. Add 45kWh more battery for another $48k. Does that seem right? Roughly $1k per kWh? By my calcs, that's approximately a $14k car with $90k in batteries added. What am I missing?