[Tuna-Fish]

The computers needed to run self-driving cars are not the expensive parts. The sensors are. And the sensors are expensive because there are so few users.

High-precision accelerometers used to be extremely expensive, with the best having prices in the high 5 figures. Then companies started putting (initially really crappy) accelerometers into smartphones, just to know which side is up. Then economies of scale hit and suddenly every smartphone has an accelerometer better than those super-expensive ones, and cost per part is pennies. (And then drones became a thing.)

The same will happen with LIDAR. Nothing about any of the parts of a self-driving car requires it to be super expensive, it's just that things that are made in quantity are cheaper than special snowflake parts.