Would projecting the outside world on the inside of a tin-can car meet the benefits ascribed to windows? (I could imagine some dystopian future where windowed cars are considered to be luxury items).
The motion-sickness reducing benefits of staring at the horizon is usually ascribed to the horizon being very far away and not moving along with the car. Until your projections are holographic, it won't help.
The up front cost of a vehicle is something like 1/3 of the cost per mile (probably less for commercially operated vehicles), so even a pretty big decrease in the purchase price will only have a moderate impact on overall cost.