...Is it worth the extra cost...
1) Autopilot can be fatal if not used as instructed.
It has many limitations that are listed in the owner's manual.
But I love using it for over a year since March 2017!
2) Autopilot will get better but it is designed to never achieve Self-driving unless you want to pay more.
Tesla self-driving has not been activated so there's no way knowing how it will be able to fulfill advertised promises.
3) At least there are 3 states that allow Self-Driving without a human driver and these are not for testing purpose only but for general use:
Florida,
Michigan,
Georgia
California now allows testing of self-driving cars without a human driver in the car BUT a human must be able to remotely control the car at all times.
4) If you know how to babysit Autopilot then the price is worth it.
If you want to donate for Self-driving cause and want to be among the early adopters to witness its incremental progress in future, it's worth it.