I spent on average 1/24h in a car, and for this I must pay more than 10$ a day + gas. If I could have a reliable and cost efficient driverless taxi service available, I'd certainly never own a car ever again. I live in a small rural town where public transportation is almost inexistant and taxi fares are expensive. I wish I could just use a car when I need to and let it go elsewhere when I don't need it. In my mind, fully autonomous cars will have a very big effect on car ownership for individuals.
If a business were to own such cars for a taxi service, there would be no much maintenance costs, just the acquisition price and power (for electric cars, and where I live power is cheap), so I think they could come up with a price that is very competitive and have a good profit margin. They would have no taxi drivers to pay and I hope the taxi licencing would be adapted to this new reality and that governments won't try to slow this revolution with heavy taxation. They should instead have a contingency plan (buying back licences, facilitate career change, etc.) for these drivers that normal technological advancement pushes out of a job.