They hired away almost half of CMUs robotics department. That's gotta be expensive. They are building (in the city no less) an autonomous driving test track/facility. That's also gotta be expensive. Human drivers are just a brief stepping-stone.
http://www.nytimes.com/2015/09/13/magazine/uber-would-like-t...
If you spend $1B on actual physical vehicles or whatever (let's say... 500 $2M vehicles), then if you have 200 employees with an average pay of say $500k per year, then you could pay them all for a decade with another $1B, meaning that you'd have spent less than 1/6th of the funding they've taken to date, or still have $1.5B left of the Saudi Royal Family's hard earned money.
More briefly: no, obviously they are not spending their money on an autonomous driving program.