For autonomous cars, the best-case component price estimates I've seen for solid-state LIDARs, assuming mass production, is $1000. I believe you need four of those, and then you need ultrasound, radar and super-hi-res cameras. And a big honking computer to process all that data. It's probably at least a $10k premium over the normal car just in additional hardware costs, and that's assuming mass production.

Then there's the cost of all that software development that companies will want to recoup, plus the cost of collecting and live-updating a vast data set of roads, pedestrian paths, local wildlife/other hazards, roadworks, local laws and regulations etc. in every big city and small town in all the world, to assist and confirm the information gathered by sensors in the car.