I think the difference I was trying to make is that Tesla was starting from zero, while other automakers already have an existing network of factories, and consistent and relatively stable capex already built into their long term financial models. Ramping up a manufacturing company from scratch is much more costly and incrementally adding manufacturing capacity to an existing company. It happens in all industries, the difference here is we haven't seen a "new" car company for generations. These drastic price drops in the Model S are a reflection of that, and as Tesla becomes bigger and more stable, you will stop seeing those decreases.
And I agree inflation adjusted prices have come down, and in large part that's due to technology making manufacturing more efficient. However, you definitely never see a particular model, say, BMW 328i, EVER drop in base price one year to the next.